Niels Steenson/Nicolaus Steno

Prelude
The Goldsmith’s Quiet Boy
The Great Anatomist
Founder of New Sciences
In the Service of Christianity

At the corner of Křbmagergade and Klareboderne in Copenhagen there stood, around 1630, an imposing two-storey building. It was burnt down in 1728 when a big fire destroyed two-fifths of the city. It must have been substantial because it was called a gĺrd, meaning here, a "town house". The insurance sum also gives some indication of its large size.

In this house was born in 1638 the great natural scientist, one of the greatest of all time, and later also a bishop, Niels Steensen. The name was Latinized as Nicolaus Stenonis, which in turn is usually contracted, less correctly, as Nicolaus Steno. In Italian it is Stenone, and in French Stenon. These various forms of the name are an indication of Steensen's international fame. He was not only a Dane, he was - and is - a European. He is part of the western and southern European culture of the seventeenth century, and especially of Christian culture. In the countries where he lived and travelled his books were invariably published in Latin, the lingua franca of those days, but his many surviving letters are in Latin, German, French and Italian, a few only in Danish. He thrived where mind and ability developed best and most freely, and he was so modern in his whole outlook and approach that it is entirely legitimate to say of him, as does the editor of his scientific works, that "he asked his questions and answered them like a scientist of the twentieth century".

Steensen's life was short but eventful - he was only forty-eight when he died. During his childhood and youth his native Copenhagen was ravaged by wars and epidemics. So he went abroad, traveling the troubled Europe of the seventeenth century, and by his brilliant anatomical discoveries in Holland soon made himself known throughout the scientific world. Subsequent years of travel in France, Italy and Germany brought him into contact with men like the biologist Marcello Malpighi and Vincenzo Viviani, the "last disciple of Galileo". He was admired by the newly founded scientific academies the Academia del Cimento, the Academic des Sciences and the Royal Society. He made the acquaintance of Spinoza and Leibniz, and he founded modern geology at the court of the Medicis. In those fertile years, however, he was already beginning to turn from science to religion. The duke of Hanover wanted him as the apostolic vicar, and he spent three hardworking years as suffragan bishop of Münster. After two strenuous years in Hamburg he died quietly and obscurely in Schwerin.

Steensen's inspired discoveries and high ethical-religious aspiration made a deep impression on like minds, and yet his life and work were rather quickly forgotten after his death, as indeed he had wished them to be. In the eighteenth century his scientific and spiritual fame was limited to a few circles. Only the advancing science of the nineteenth century was to become aware of his brilliant work. It was then realized how many anatomical and physiological problems he had elucidated; that the science of paleontology (the study of fossils) began with him; and that he is to be regarded as the father of modern geology and crystallography, which owes to him its most important law, that of the constancy of angles. An eminent modern medical historian, Max Neuburger, declared of Steensen's brain anatomy: "Like the flash of lightning in the night, shedding a flood of light suddenly and clearly on the wild host of clouds, so does Steensen rise above his contemporaries". The young geologist K. Mieleitner compares Steensen to the mythical King Midas of Phrygia, who turned everything that he touched into gold.

Of the spiritual personality and the Steensen engrossed in God, A.D. Jřrgensen, keeper of the Danish national records, says, at the end of his biography of Steensen: "It is the simple greatness of the apostolic age itself which here advances to meet us... he had the promise of Christianity: blessed be they that hunger and thirst after righteousness, for they shall be filled". Words such as these from a non-Catholic source explain the recent Catholic moves for Steensen's canonization. As Cardinal Dr. Julius Döpfner has said: "One wonders whether this European personality, this tireless diaspora apostle, might not to a special degree be a pattern and patron for our century, characterized as it is by great advances in the natural sciences, serious endeavors toward European unity, and a deep longing for Una Sancta?"

When Niels Steensen was born on New Year's Day (Julian calendar) 1638, Denmark was still a Baltic power with provinces on both sides of the Sound, which now separates it from Sweden. The blissful time of Christian IV, however, was a thing of the past; Wallenstein's soldiers had already carried the Thirty Years War to the northernmost tip of Jutland ten years earlier. But the boy knew his native city of Copenhagen in the lustre shed on the old fortified town by the king's appetite for building for "the good and gain" of its 25,000 inhabitants. In Gammeltorv square they had a new town hall, Copenhagen's third; new churches had been built, among them Holmens Kirke for naval personnel; and Vor Frue, the cathedral, had been given a new spire. Outside the ramparts, a park, Kongens Have, with a summer house, was laid out eventually to become Rosenborg, a romantic royal palace.

Also outside the old town, free quarters for the king's "shipment" were built, a whole neighborhood of single-storey row houses with intermediate gardens, called Nyboder. Its fine yellow-washed lengths have since had an extra storey added, but it still serves its original purpose and is a memorial to a farsighted and able builder whose architectural interests went far beyond palaces and churches for his own glorification. Most remarkable of all was Rundetĺrn (the Round Tower), which was begun in 1637, the year before Steensen was born. It was completed by 1642, and the boy's parents will have been able to tell him - long before he began to attend school in this area - that the tall tower was now to be used in order the better to see and study the stars.

Walking along Křbmagergade they would pass Sct. Nicolai, the family's parish church, where Niels was baptized and where, later, his father and mother were to be buried. Further down stood Holmens Kirke and, facing it, the newly completed Bourse, probably the handsomest of the king's buildings, in the individual Netherlands Renaissance style that has actually been named after him (Christian IV's style). And just across the harbor mouth, on the island of Amager, an entirely new town was laid out, called Christianshavn after the king. It was designed on the lines of Italian town planning, and Niels Steensen may well have observed, some ten years later, that Livorno (Leghorn) in Italy was laid out on the same system. The king also provided for a good connection across the "swell" in the shape of the first Knippelsbro, a piece of bridge-building the city was very proud of. All this made sense of its name "the King's Copenhagen".

Even more than the king's power, the king's gold would have impressed the boy when he saw it in his father's workshop. Sten Pedersen came from Skĺne on the other side of the Sound and of a respected clerical family. He had chosen the craft of goldsmith himself, and we find him back in 1620 occupying a leading place among his fellow-craftsmen in Copenhagen, and purveyor to the royal court. He had his workshop in the big building at the corner of Křbmagergade and Klareboderne, and here, too, were both a wine cellar, where "wine, spirits, etc." were served, and the family home.

Of the mother, Anne Nielsdatter, we know very little; Steensen never mentions her. Both parents had been married before, and Anne would do so twice more to goldsmiths before being finally laid to rest in St. Nicolai church. Niels Steensen has told that from his third to his sixth year he suffered from a troublesome complaint which kept him from playing with his contemporaries and led him instead to listen to the conversation of grown-ups, especially when the subject was religion. He valued this intercourse so much that later in life he would seek out the company of mature and especially religious men. Steensen was afflicted with poor health all his life, and was described when grown up as small and slight, frail in stature. Nor do the remains of his skeleton indicate a robust physique; yet there is much to suggest that he inherited from his forebears, who lived relatively long lives, an exceptionally tough constitution and could subject himself to the most incredible exertions. One need only recall his mountaineering in the Alps and elsewhere, and his great powers of endurance when working.

Steensen would have made his first "expeditions" from the closer family circle to the exciting gold and silver workshop, drawn by the hammering heard distantly in the home and ringing loudly from the heavy anvil in the workshop itself. His father would have reverently unlocked drawers and cabinets to show his young son the gold, the silver and the gems, and the curious and inquiring boy would have wondered what caused the strange refractions in these crystals. He would also have gone round among the craftsmen, watching them making knives, forks and spoons; while on walls and in windows there would have been finished ornaments in gold and silver hung up for display. No doubt, too, he would have sensed the excitement spreading suddenly from master to apprentice when the powerful figure of Christian himself looked in to ask how things were going with some commissioned silver tableware.

Steensen told later of how highly his father stood in the king's favors, thanks to his craftsmanship, piety and culture, and of how once - probably when the business was to be modernized - His Majesty had lent him the large sum of 300 rigsdaler, repayable only six years later. On the other hand, the good Sten Pedersen would occasionally have to put up with the even longer time that it took the king to pay his bills as the royal purse not infrequently was at a low ebb. Many of Christian IV's buildings bear the initials RFP of his Latin motto (Piety fortifies the realms), which were Regna Firmat Pietas - popularly interpreted as meaning Riget fattes penge (The realm lacks money).

If it was exciting to watch his father and the men wielding their tools, the boy Niels would find it even more enjoyable to handle them himself, making the delightful discovery of how good he was with his hands. He would soon learn how much could be done with a light touch, provided one could quickly assess the possibilities, and many hours spent in the busy workshop would have developed his inherent dexterity in the best imaginable way. As an anatomist, he became great not only as a scientist but also as a craftsman. His father's workshop would be his first experimental laboratory, the place where his interest in natural and technical science would be encouraged until, age twenty-one, he left home. His own notes show that when a boy he measured the weight and cubic content of gold and he also described hydraulic machines and determined the cubic content of expelled air. He constructed a microscope and studied the refractions of light by means of two lenses fixed to a rod. He made chemical studies of sulphur and saltpeter, and produced red dye from vitriol. No interesting possibility of probing the mysteries of nature escaped his ever alert mind. Good financial circumstances and a harmonious family life supported the boy in his quiet research and provided him with a secure adolescence.

When the boy was big enough to be allowed outside the corner house on his own he may well have crossed the street to the opposite neighbor at the corner of Křbmagergade and Lřvstrćde. Here lived Joachim Schumacher, a Rhenish wine merchant and wine bar proprietor who was an immigrant German, and Niels may well have chatted there with the eldest son, Peder, two years or so older than himself. This boy would, as Peder Griffenfeld, become the country's greatest statesman of the century, and the two would have dealings with each other later. What the playwright and historian Ludvig Holberg said of Griffenfeld rather more than a century after may be applied to both: both can be "reckoned among the singular men Denmark can exhibit as a sample of what this Northern climate can produce".

Niels Steensen's esteemed and respected father died as early as in 1644. A year or two later, his mother married the goldsmith Johann Stichmann, who had probably come in from Germany (his bills are written in German), and who now took over the business. It is not known where the boy first attended school, but it may well have been under the well-known David Skolemester, whose school was near his home. But at the age of ten he took the short and familiar way up Křbmagergade, turning left at the Round Tower into the cathedral square, there to be enrolled in the country's most exclusive school, Vor Frue School, which had been established right back in the time of Bishop Absalon, the city's founder. Here, in the old humanistic grammar school, was laid the foundation of his knowledge of mathematics and languages. The boy will no doubt have had an easy time of it at school. As already indicated, he had a talent for languages, and in his short life acquired a knowledge, besides Danish, of German, Dutch, French and Italian, plus Latin of course, and he also learnt Greek, Hebrew and Arabic.

The school's headmaster was Jřrgen Eilersen (Latinized as Georgius Hilarius), whose mathematical abilities later won him a professorship at Copenhagen University. He was also a good teacher and behaved like a father to his pupils, especially in the dreadful plague year of 1654-55 when more than 8,000 people died - a third of the population of Copenhagen. At Vor Frue School 240 died - about every other pupil - and sixty were buried on one day alone. It is easy to understand that "the tyranny of death" - the expression of his contemporary, the hymn-writer Thomas Kingo - must have affected a nature like Steensen's, and will have contributed to the forming of his outlook, as expressed a few years later: "Grant, O God, that we may always have on our lips the words Memento mori".

One of the masters at Vor Frue School, to whom Steensen felt some attachment all his life, was Ole Borch. He was a gifted teacher of Greek and Latin, but was best known for his botanical excursions in the environs of Copenhagen and the chemical experiments he performed in a laboratory provided for him by his patron, the seneschal Joachim Gersdorff. In forceful imagery, Borch speaks of "experiment as the right royal road to the perception of truth", and he showed genius in some of his research.

The isolation of his early childhood does not seem to have cut the schoolboy off from boys of his own age. This is shown by a little aside in one of Steensen's last letters. Shortly before his death, he met in Hamburg one Jacob Henrik Paulli, and says of him: "He was a son of His Majesty's first physician with whom I was brought up in Copenhagen". Simon Paulli, the royal physician, who came from Rostock in Germany, was also an inspiring anatomist and botanist at Copenhagen University. He is best known for having instituted in 1645 the anatomical theater, called domus anatomica, and for the publication of the great botanical work Flora Danica. The court physician was a fascinating teacher, who used to take his pupils on long excursions so they could make their own independent studies.

At his house in Copenhagen's university quarter, Steensen associated with Paulli's two intelligent sons in common interests that made the learned master of the house his fatherly friend. With him, the three boys would doubtless have paid frequent visits to the anatomical theater and have been fascinated by its many animal and human skeletons. And a cheerful array of pictures with racy texts in Paulli's house would both have amused the boy and given him food for thought. Inscribed on a window frame were the words: "O man, remember eternity! God's eye is upon you!" Somewhere else he would read: "Live with death in your thoughts: time hurries, we are shadows!" These were texts that would come to match Steensen's own philosophy of life. Others convey a sense of the atmosphere in which the boy grew up. Above the kitchen door, for example, stood the words: "A rich kitchen is the mother of sickness". They may have served as an apt warning in a city where King Christian's orgies of eating and drinking were whispered in every corner. Finally, in the family's poultry yard there was a picture of a "brazen woman boastfully displaying a very large ostrich egg in her outstretched hand. On her right was the ostrich itself, and on her left a poor peasant offering small hen eggs for sale". The moral of the picture was that a hen lays an egg every day, an ostrich only once a year; in other words, a small and regular income is more enduring than a large and infrequent one.

In Steensen's time, modern natural science emerged triumphant; in 1642 Galieleo died, and in 1643 Newton was born. Denmark had its great astronomer Tycho Brahe and men like Peder Sřrensen, a friend of Paracelsus, whose fervid challenge must have fired young minds when he asked them to burn their books and buy stout shoes in order to go into the mountains or to the seashore to observe and experiment. When Steensen matriculated at Copenhagen University in 1656, he chose as his tutor the eminent physician Thomas Bartholin, famous even then for his demonstration and description of the lymphatic system. Steensen would doubtless already have attended some of his demonstrations as a pupil at Vor Frue school in the anatomical theater; but was not to enjoy his teaching for very long at the university, and altogether could hardly have found a more difficult time for his studies. Academic life was still suffering from the effects of the great plague, and before the end of 1656 Bartholin retired from medical teaching in order to devote himself to writing and publishing his manuals on anatomy that were used all over Europe. Furthermore, Steensen's studies coincided with a period when the kingdom of Denmark might have been wiped out.

Midsummer 1657 saw the outbreak of the first war with Sweden, whose war-trained army, after various successful engagements on the Continent, crossed the ice-bound Danish waters to Zealand where the king, Frederik III, avoided the threatened capture of Copenhagen by a swift capitulation. The country then enjoyed some months of precarious peace, the price of which was the cession of the Scanean provinces, the Steensen's homeland. But hostilities broke out afresh in August 1658, and for nearly two years Copenhagen was besieged by the Swedes. Everyone, headed by the king shared in the heroic defense, including the university students. Among them "Niels Stensřn Hauniensis", whose stepfather Johann Stichmann, as captain, commanded the Křbmager quarter's company and its 409 citizens.

In their attempt to storm the city in the night of 10-11 February 1659 the Swedes suffered a decisive defeat, to which, in the words of a contemporary report, "most of the Swedes brought their shrouds". The national rising had made the citizenry allies of the king, soon to be absolutist; and when Copenhagen got a council of 32 of its "best men" to assist the corporation nominated by the king, Johann Stichmann was one of them. Even greater was the joy and pride in the goldsmith's home when, together with eight others, the king decorated him with a gold neck chain for brave service. Dignified, and aware of his responsibility, he was not afraid, later on, to set his signature to petitions to the king, often bold ones when the matter concerned the city's welfare.

Steensen's studies in these disastrous years must have involved a period of intense intellectual activity. The best evidence that we have for this is a notebook dating from then. Containing nearly a hundred closely written, double-column foolscap pages, it is titled - perhaps because of its mixed contents - Chaos. Discovered in 1946, it is now in the National Library in Florence. It reveals that he read about a hundred scientific works by about eighty authors. Among others, he knew Kepler's paper on hexagonal snow; it is characteristic of him that he was not satisfied until he had seen it for himself. Barely a month after the storming of Copenhagen - on 8 March 1659, when a hostile Swedish army still surrounded the city - he went out into the snow in the inner city, avid for knowledge. Allowing the delicate snow crystals to drift on to his hand, he watched them melt and evaporate, leaving no trace of their beautiful forms; but he copied them on a scrap of paper in order to study them later. He also read Galileo and Copernicus; the correctness or otherwise of the Copernican system, with the sun as the center of the universe, being then widely debated.

Tycho Brahe for his part could not accept it, as it was incapable of proof with the imperfect instruments of that time, but the 20-year-old Steensen was inclined to agree with Copernicus. He certainly subscribed to the new scientific method. "In natural science", he wrote "we know only experiments and observation, together with what we can deduce from them with the help of metaphysical and mechanical principles". It is remarkable that Steensen was also familiar even in these student years with the mathematical-philosophical genius of the age, Rene Descartes, and that he consciously adopted his approach, which was to doubt everything in order to arrive at a certain knowledge. One perceives in the young student's notes a prudent, critical and independent approach to everything that he read.

The Chaos manuscript, beginning "In the name of Jesus", also affords an insight into the young Steensen's religious mind. His devoutness appears no less marked than his lively scientific interest. In the light of the intolerance of those days, it is astonishing to find many extracts from a devotional book by the court chaplain in Munich, the Jesuit Jeremias Drexel, entitled Description of Joseph, Vice-regent of Egypt.

In the light of the Chaos notes, it is not surprising that there were many discussions in Steensen's Copenhagen home on where he should go for further education, for it was already plain that there was little more for him to learn there. The student was outstripping all his teachers in knowledge and learning, and his heart was set on the scholarship of Europe. The matter was also discussed with Thomas Bartholin, who would undoubtedly have regarded Amsterdam and Leyden as the most suitable places. Bartholin was also able to give him a letter of recommendation to a professor in Amsterdam. Apparently in the autumn of 1659, Steensen left Denmark to embark on his journey for science.

Way back in the earliest Middle Ages, it was customary for able young Danish students to go south to the great universities, notably the Sorbonne in Paris. In early times, the principal subjects of study were theology and philosophy; the natural sciences, including medicine, came later. A student interested in the natural sciences and mathematics in the seventeenth century and wanting the best education could attend the university of Leyden, founded in 1575.

History tells us that the connection between Denmark and the political and cultural great power Holland at that time was a very lively one. In the period 1575-1700, nearly a thousand Danes studied at Leyden. Owing to their abilities many Dutchmen obtained good positions in Denmark, and not infrequently Dutch money was a necessity, especially for financing wars. Many Danes signed on as seamen on Dutch ships, and a would-be merchant who aspired to the best training would look to the great merchant quarters of Amsterdam, where, among other things, we first hear of special training in book-keeping. Material prosperity has often been followed by intellectual greatness, the art which made Holland a cultural force being painting. Her greatest painter, Rembrandt, was still active when Steensen went abroad.

His first destination was Rostock in Germany, where his fatherly friend Simon Paulli was able to get him every possible contact, but soon he went on to Holland which had just assisted Denmark at a time of need, and which was then in the midst of its golden age. Steensen arrived in Amsterdam - which at that time was three or four times as large as Copenhagen - in March 1660, and it was clear three weeks after his arrival that his apprenticeship, so to speak, had ended, and that among scholars he was an equal.

The academic life at Amsterdam's Athenaeum was still fairly new, but the city possessed several hospitals and a hall where anatomical studies could be carried out. Here, on 7 April, Steensen dissected the head of a sheep, making his first discovery by finding the excretory duct of the salivary gland. At once modest and full of a beginner's joy in research, he tells of it in a letter to Thomas Bartholin: "Having been allowed to dissect on my own, I succeeded in the first sheep's head which I purchased and dissected by myself in the study hall on 7 April in finding a duct which - as far as I know - has not previously been described. It was my intention after removing the ordinary outer parts to do a section of the brain when I happened to decide first to examine the vessels running through the mouth. Examining with that intention the course of the veins and arteries, by inserting a probe I observed that the point is no longer enclosed in the narrow sheath but moves freely in a spacious cavity; and pushing the instrument further forward, I at once heard it clink against the teeth themselves".

Elsewhere in his letter to Bartholin, Steensen modestly calls his discovery an inventiuncula - a small observation. In a way, it was this inventiuncula that would make him most famous, because, the duct of the parotid gland was named, by one of his Dutch friends, the Ductus stenonianus, and doctors throughout the world still call this duct, which supplies the mouth with most of the saliva needed for digestion, Steensen's duct - including all those who do not know who Steensen was.

Steensen had of course summoned his professor - and landlord/host - Gerard Bläes (Blasius) to show him his discovery. It was at once dismissed as a badly performed dissection. But on further reflection, Bläes claimed the duct as his own discovery, and in a brief publication entitled General Medicine in the spring of 1661 laid public claim to it. The prolonged dispute about the discovery had only one result, which was to lead the young Dane on to a succession of further discoveries. Actually, Steensen stayed for only a few months in Amsterdam, probably according to plan, but like his Dutch friends he would continually return to this center of culture. He made a number of new friends during his short stay. The one he may have liked best was his contemporary fellow student Jan Swammerdam, one of the truly great zoologists, and one of the first to use a microscope in scientific studies. The two would meet one another frequently in the future. Steensen concluded his studies in Amsterdam with one of the most popular disputations of the time when, with Arnold Senguerd, professor of philosophy, presiding, he defended a short thesis on hot springs.

From Amsterdam Steensen went on to Leyden, where he enrolled at the university on 27 July 1660. The three years there were to be his most fruitful ones in the field of anatomy, making his name known far beyond Holland. He published ten papers in this period. Among the professors he particularly attached himself to were the Amsterdamer Johannes van Home, whose work was chiefly done on the reproductive organs, and Frans de la Böe (Franciscus Sylvius), who had not only distinguished himself with his contributions to the knowledge of glands and the brain but was also an admired and inspiring academic teacher. Among natural scientists besides Swammerdam whom Steensen also met here was Reiner de Graaf. Dissecting was carried out avidly in Leyden's famous anatomical theater as well as at the hospital, and there was clinical instruction as well.

Steensen appeared before the public as an independent research worker with his dissertation: "On the glands of the mouth and recently discovered ducts", of 6-9 July 1661, with van Horne presiding. He described factually and fully in this paper his old discovery of Steensen's duct, but went much further in announcing a number of other gland discoveries and discussing the problem of the general importance of glands. Quietly, he now began to assemble these and other findings on glands in a publication, Anatomical Observations, which appeared early in 1662. This little book of four papers (including his dissertation) was respectfully dedicated to his teachers in Copenhagen and Leyden, among them the mathematician Jakob Golius. Gerard Bläes made a few last desperate efforts to assert his claim, and was briefly refuted by Steensen in his Precursor to an Apology of 1663, in which he demonstrated the difference between his duct and the one described by Bläes - which, other than the "discoverer", was known to no-one but the man in the moon.

The Dutch period was a rich one; but given Steensen's versatility and receptiveness it was also a period of scientific crisis, which very nearly diverted him from anatomy, together with a religious crisis that almost cost him his Christian faith. A letter of 26 August 1662 reveals a wish, already at the beginning of that year, to exchange the blooded dissection scalpel for the geometrical compass. This revival of his love of a mathematically exact understanding of nature is not surprising, for Steensen encountered it everywhere in the Netherlands. His friend Swammerdam, the great biologist, was then occupied, as he still was on his deathbed, with a planned work on bees, "in which the wisdom and omnipotence of God were demonstrated most mathematically". And for the ever open-minded Steensen it was an experience during vacations to travel round the Netherlands with his Danish friends, headed by Ole Borch. There can be no doubt that his sense of the country's scenery, and especially its geological structure, was sharpened on these tours, and everywhere the travellers encountered high technical development based on Steensen's favorite subject, mathematics.

One of these tours took them to the rich and fertile regions, with their flourishing towns, of North Holland. Through wooded tracts and large expanses of heath land they arrived at landscapes that had formerly been sea but now were dammed behind dikes, and by human energy and ingenuity transformed into fine woodlands and friendly villages. They visited Enkhuizen, which mustered a fleet of 400 ships for herring fishing, and at Zaandam they inspected Holland's biggest shipyard, with 40 completed ships and an oil press. Then another tour to Belgium, where, at Brussels they studied art and the fine buildings. At Antwerp they visited the Waterhuis brewery, with its great pumping installation, and at Louvain the university's anatomy hall. Via Ostende they reached Dunkirk, from where on a clear morning Steensen could look across to England, whose shores, however, he was never to tread. Everywhere it was a great and enriching experience for the small band of Danish travellers to pay their respects to famous scientists. At Zaandam, for instance, they met Thomas Walgensten, from Gotland, who was to invent the magic lantern. Holland was in those days one of the leading producers of optical instruments.

Of the greatest importance to Steensen personally was making the acquaintance of Baruch Spinoza, the celebrated Jewish philosopher. He lived in the small town of Rijnsburg near Leyden, where, not least by his simple life, he attracted many of the students of Leyden university, among them Steensen. But for the young Dane, as for many others in liberal Holland, the open discussion of the various faiths engendered a religious crisis, leading him to view Lutheranism with greater scepticism. Spinoza's own philosophy of life, however, was remote from his. Spinoza believed that nature and God are identical and that everything must be understood in the light of nature itself, which is an indivisible whole. This conflicted in every way with Steensen's belief in a personal God. As he himself put it, he was delivered from this "idealization of human thought" in a truly wonderful way, since at that very time he made the discovery "of the heart and the true structure of muscles, which without words, merely by inspection, turned all the most sophisticated figments of the mind upside down".

Steensen was alluding to purely speculative adherence by Spinoza and his disciples to the explanation of the heart by the ancient Greek physician Galen as "a close tissue and the seat of the ardor of life, but not a muscle". His own studies, which then went ahead, led him not only to understand the structure of the muscles of the tongue, gullet and respiratory organs but soon to the point which he later describes in a letter to Leibniz. He had bought and cooked the heart of an ox, and while loosening fibre after fibre from the well-prepared organ, he established its muscular structure. At the same time he lost his respect for Spinoza and the rationalistic assurance with which he would solve man's moral and religious problems simply by geometrical means. When these men, he concluded, men whom the world worships as wise, proclaim as infallible evidence what I can get a ten-year-old boy to refute by a simple preparation, what assurance can they offer me when they discuss God and the spirit? Probably at this time Steensen - the biologist and Christian believer - conceived the idea for his fine coat of arms - a heart crowned by a cross.

Late in the autumn of 1663, Steensen must have received news from home of the death of his stepfather Johann Stichmann. He was forced to break off his brilliant studies, and such were the circumstances, he says, that they "robbed me of all hope of ever returning to them". In March 1664 he was back in Copenhagen, and the city's son, who four years before had gone out as an unknown student, could now lay the fruits of four years' anatomical work "before his exalted and mighty King Frederik III" in his treatise On Muscles and Glands, which the Swiss poet and naturalist Albrecht von Haller (1700-77) called a "golden little book". Two appended papers show that Steensen continued his discoveries on the home ground. One, On the Anatomy of the Ray, describes the dissection of two rays which he had performed three days before in the house of his fatherly friend Professor Paulli, and which led to a number of new findings on the fish's mucous duct, reproductive organs and respiration. The other paper, On the Yolk Duct to the Intestines of the Chick, deals with a sensational discovery, one which Aristotle had made but which had long since been forgotten, that the chick's nourishment is drawn direct from the yolk through a connection duct to the intestine.

While he was putting the finishing touches to this paper, which is dated 12 June, Steensen had the great sorrow of losing his mother, and the young scientist must soon after have realized that now, more than ever, he had to look around for a living, and that at any rate he could not reckon on a university appointment in his native city. The prospects of this would otherwise seem to have been favorable. The study of anatomy was then rather neglected in Copenhagen, and Thomas Bartholin had already complained in 1667 that the Theatrum Anatomicum was covered in dust. The failure in these circumstances to enroll such a highly qualified anatomist as Steensen on the teaching staff of the university has often been ascribed to the nepotism of the reigning professor family, the Bartholins. Steensen himself conceived the idea, now when nothing tied him to the home any longer, of spending the 300 rigsdaler left him by his mother on continuing his studies abroad, and there perhaps obtaining the post he was unable to get in Denmark.

Steensen did not return to Holland but went straight to France, possibly because his friends Borch and Swammerdam were there. But from Leyden news soon came that for his "uncommon learning" he had been made a doctor of medicine in absentia, without having to write a special treatise. By then he had already gained admittance to Melchisedec Thevenot, the scholarly patron who subsequently became Louis XIV's librarian. At Thevenot's house in Paris or on his farm near Issy were held the learned meetings that a year later would lead to the establishment of the royal Academie des Sciences. Steensen was also associated with the circle of Pierre Bourdelot, the well-known physician who had once treated Queen Christina of Sweden. The prominent journal Journal des Scavans wrote in laudatory terms of the Danish scientist and his visiting lectures at the official university thus: "The Danish scholar performs dissections daily in the presence of many inquiring men. He has evoked everyone's admiration by his new discoveries; for the remarkable fact about him is that he does most of what he undertakes so tangibly that one has to be convinced, and one must be surprised that this can have escaped every earlier anatomist".

Several more embryological papers were produced at this time, though not published until much later, including Observations of Eggs and Chickens. How fruitful and thorough these studies were has been realized in our own time. In the short paper Dissection of a Monstrous Foetus in Paris was found, quite unexpectedly, the first description of tetralogy, the discoloring of the skin known as "blue baby" due to congenital heart disease that is often called after the French doctor Fallot, who made his observation 200 years after Steensen.

The great immediate scientific event of that Paris winter, however, was the meeting in the Thevenot circle at which Steensen delivered, in French, his most elegant lecture, Discours sur l'anatomie du cerveau, revealing himself spontaneously, so to speak, as the supreme brain anatomist. He began by saying how ignorant he was of the brain, this "the most beautiful masterpiece of nature", that is the principal organ of our mind. "Our mind thinks that nothing can set a limit to its knowledge, but when it withdraws to its own habitation it is unable to give a description of it, and no longer knows itself". With good reason, he criticized earlier theories that the brain was connected with the mind through an egg-shaped gland. That sort of thing was no more than ingenious speculation, Steensen declared, and he compared the brain with a machine that one could understand only by taking it to pieces down to its smallest parts.

One of the most valuable aspects of the lecture - and the short paper written later - is the demonstration of the principles and methods that future research should follow in order to arrive at certain knowledge. Even at this stage, Steensen was far in advance of his learned contemporaries, who were captives of the current systems. Steensen does not draw his inspiration from classical and later literature but starts out right from the beginning with basic and unprejudiced first-hand observations, in which he is able to a rare degree to pick on the essential. From there he develops his own theories link by link, accompanied all the time by critical reflections. He also anticipates the complementarily theory of today by constantly pointing out the influence of the observation on what is observed.

Together with later works, the lecture establishes Steensen as one of the pioneers of the science called comparative anatomy; that is to say, the study of a definite organ in many animal species and in man, followed by their comparison. The method leads to a far better perception of the function of the individual organ. Steensen himself examined a number of mammals, fishes and birds, and said: "...there are always conspicuous differences". When the lecture was published, Steensen supplemented it with some sketches. These were long neglected, but a closer modern inspection of them has shown them to contain a number of details unmentioned in the text.

Steensen's lecture must have had a startling effect on his audience, because - here, in one of the centers of Cartesianism - he contradicted it by asserting that man alone has a soul or mind, whereas animals are merely machines in which everything is purely mechanical, as in inanimate matter. Their religious disagreement may also have revealed itself. But we do not know whether his scruples led Steensen at that time to the Jesuit college or the Port Royal that all Paris was talking of as the haunt of a circle of gifted men who lived for religion without monastic ties. He himself recalls only at a later date his discussions with the pious Hedwig M.E. Rantzau, widow of Josias Rantzau, marshal of France, and many years after he thanks Thevenot's niece, an otherwise rather unknown Mlle Perriquet, ascribing to her no small share in his religious development.

In the late summer of 1665, Steensen - to his many newfound friends' regret - left Paris in order to travel around France. Going through the Loire valley, he proceeded via Angers and Bordeaux to the old university town of Montpellier, where he made the acquaintance of a number of eminent British natural scientists. One of these was Martin Lister, who in December attended a dissection by Steensen in the Earl of Aylesbury's study and praised "the man's genius and great personal modesty". William Croone was another of Steensen's friends, and was his link with the young Royal Society. Recently discovered letters, reveal that, together with the learned Englishmen, he made geological studies. It was the science in which he would subsequently make his greatest contribution. But that was in Italy.

In the spring of 1666, Steensen stepped for the first time on Italian soil. We find him at Pisa, the winter residence of the grand duke of Tuscany. Ferdinand II, under whom the Medici family was to experience its last cultural flowering, was known for his support of art and science, a patronage necessary for Steensen, who lacked private means or a regular post. The capital of the grand duchy of Tuscany was Florence, one of the great centers of Italian civilization, and one where natural science especially was pursued in a manner attractive to Steensen. It was here that Galileo had worked, applying the experimental method in his science, and he had been an ardent believer in the Copernican system. He had died in 1642, but his spirit and ideas lived on in his disciples.

Steensen had been given letters of recommendation in Paris, and they got him such a cordial reception by the grand duke that he remembered it movingly many years after. Florence was to be the place where he would always feel at home, and would reach the climax of his scientific career. There also he would arrive at the form of Christian faith which, in accordance with his nature, he felt was the only true one; and there he would find his last resting place in the burial church of the Medicis themselves, San Lorenzo.

Steensen did not, however, go direct from Pisa to Florence. When the Medici court moved back to Florence before Easter, he, keeping to his original itinerary, went south, and in April we find him in Rome, the Rome of the Baroque period under the highly civilized Pope Alexander VII. At a banquet in the Villa Ludovisi, Steensen made friends with Marcello Malpighi, the great Italian biologist who had already inscribed his name with luster in the history of science, inter alla by his two epistles on the structure of the lungs.

Another member of the party, G.G. Riva, deserves mention. Not only as an eminent surgeon at Rome's famous Ospidale di S. Maria della Consolazione, but also as the founder of a museum and an academy whose meetings Steensen attended. Among other important people he met in that Roman spring were the greatest Italian opticians of the time, Eustachio Divini and Giuseppe Campani, and the later cardinal Michel Angelo Ricci, who had just published a short but valuable paper on the calculation of tangents. Steensen also visited the Jesuits at the distinguished Collegium Romanum, including the famous German-born polyhistor Athanasius Kircher, with his celebrated museum. He had talks, too, with the college fathers on problems of faith, talks whose substance is unknown; but a deeper impression was made on him by an experience later on in this journey, at Livorno. On 24 June, he witnessed in this great port the annual Corpus Christi procession in the Piazza Grande. When he saw the devout crowds united in pious homage to the sacrament, it struck Steensen: "either this host is no more than a piece of bread, and they are fools who pay it such homage, or it really does contain the body of Jesus Christ, and why do I not also honor it?". He was impelled to study this problem further.

In Florence, the grand duke Ferdinand granted the Danish scientist a monthly stipend and appointed him anatomist of S. Maria Nuova, with the right to use the great hospital's special departments for wounded and patients with stone, and not least its student college with anatomy hall. The grand duke himself was interested in natural history, and had his own laboratories in the palace where he made his own instruments. In the company of his scientific friends, he preferred to be a private citizen, the equal of the rest. The same may be said of his brother Leopold, who in his youth had had Galileo as a teacher. His greatest service, perhaps, was the institution and direction of the Accademia del Cimento, the experimental academy which, under the motto Provando e riprovando (test and re-test), had engaged in experimental science in the Palazzo Pitti since 1657.

As in Holland, Steensen made many good friends, in the circle of the experimental academy, for example the "last Galileo disciple" Vincenzo Viviani, who in his early youth had lodged with the blind old master of Arcetri and now was the grand duke's mathematician and engineer. The first fruit of this friendship was Steensen's treatise on The Elements of Muscular Knowledge, one of his major works, published in 1667. The main purpose of the paper - besides announcing new muscular discoveries - was a geometrical demonstration that the volume of the mass of muscle is not appreciably increased by contraction.

The Elements of Muscular Knowledge concludes with two accounts of dissections that were to have the greatest consequences for scientific history. In October 1666, some French fishermen had observed, off the coast of Livorno, an immense shark - a Lamia or Carcarodon Rondeletti, as it was called at that time - and had managed to haul the creature ashore and secure it to a tree in order to kill it. The shark's weight was estimated at about 1,700 kilograms; but after removing the liver, which weighed 150 kilograms, and cutting the head off, the fishermen threw the rest back into the sea. At Ferdinand's command, the head was sent to Florence for examination by Steensen. In the course of a month, the latter had written his report, Dissection of a Shark.

The first part of this short paper is a continuation of his fish studies, and concerns the mucous duct system - the skin with its lateral tube of sensory cells, the internal auditory organ behind the eye, etc. - in short, anatomical studies. The final section deals with the teeth, and it was the study of these that was to break new ground by introducing him to entirely new sciences, namely paleontology, geology and crystallography. Continuing these studies, subsequently, he contemplated writing a large work on the subjects, but many obstacles, and especially the fact that in 1967 he converted to the Roman Catholic faith, prevented him from realizing the plans. Fortunately, however, he decided to publish a provisional account of his studies. This little book, which more than any other was to be his main work, was published in Florence in 1669, after a temporary departure from the city. Its title is De solido intro solidum naturaliter contento dissertationis prodromus (Provisional dissertation on solid bodies naturally embedded in other solids) - a prolix but very pregnant title. In Danish - indeed international - science history this paper ranks with the greatest.

Studying the pointed teeth staring at him row after row in the shark's jaws, Steensen was surprised at their large number, and failed to understand why the inmost rows were curved inwards and partly concealed. He realized later that these were reserve teeth, and that the shark does not use its teeth for chewing, but for catching its prey. The transition from anatomy to paleontology occurred when it struck him how much the shark's teeth resembled Glossopterae, which could be found in large numbers in Malta especially. We know now that they are fossilized sharks' teeth, but in those days there were all manner of fantastic explanations of the phenomenon.

At first, Steensen, too, was very cautious about comparing the shark's teeth and Glossopterae. He wrote: "I have not yet arrived at a firm conviction as regards this for me to submit my own judgment". All he would do was indicate a few points suggesting that the fossils derived from animals, and he concludes by saying: "Those who proclaim the large Glossopterae to be sharks' teeth do not seem to me to be very far from the truth". But eventually - in De Solido - he is no longer in any doubt that Glossopterae are fossilized sharks' teeth, and that all manner of animals and plants, or parts thereof, from the earth's successive ages are to be found as fossils.

As Steensen himself suggested, only a few men before him had the right idea, among them - one might almost say of course - Leonardo da Vinci. But few before Steensen had made systematic studies and undertaken the laborious demonstration. Against the fossils theory it can be objected, he thought, that they consist of other matter than living animals and plants, but this can easily be transformed by chemical processes without affecting the form. The results Steensen arrived at were based to a large extent on studies of mussel shells, whose structure and organic origin he described, so thoroughly indeed that his conclusions can nearly all be accepted today.

Now that Steensen was sure that Glossopterae were fossilized sharks' teeth, a number of fresh problems arose. Why should fossilized sharks' teeth be found in the ground, when sharks live in the sea? The rocks which embedded the fossils had also to be studied, giving rise to still further problems. In studying the surrounding stratum, Steensen embarked upon an entirely new science, geology, which has thus naturally grown out of paleontology. The most important result he should take account of was that the earth's strata were sediments of a liquid, "because the finely distributed matter of which the strata consist can only have been introduced into it by the whole being absorbed in a liquid and depositing itself by its own weight, thereby being smoothed by the motion of the above liquid". Further, "the finely distributed matter of which the sediments consist closely surrounded the embedded bodies, filling out their smallest cavities".

Steensen thus came to realize that the earth was for long periods in the past covered by sea, which deposited the strata, which later became hardened. The fact that the strata are no longer always horizontal is due to the operation of currents of water and volcanic action. In this connection Steensen also speaks of the formation of mountains, which can originate in various ways, among others from volcanoes, and "by heavy rain and violent operation of mountain streams". He discusses, too, metal and mineral deposits, the aspect of geology that is of practical interest; and it is still a fact that mining and scientific studies often go hand in hand. Today we need only consider the search for oil in the seas, where geological science is an absolute precondition.

A third subject of discussion was the study of crystals. He did not know himself how crystals originated, he said, but he realized how they grew: "A rock crystal grows by new crystalline matter being deposited on the surface of the crystal already formed". His greatest contribution in this field certainly is his establishment of the law of angle constancy. The underlying idea of this is that although individual crystal surfaces of the same matter can vary in size, the angles between the surfaces are constant. It is the discovery of this law which makes Steensen the real founder of crystallography, for which reason it is now generally known as Steno's law. He did not, however, present a definite formulation, but in an appendix to De Solido drew some figures of crystals, and it is clear from the description that he made the right discovery.

De Solido concludes with a chapter on the Tuscan landscape. Steensen speaks of six different periods in the region's geological development, and says, finally: "This I prove about Tuscany.. . and confirm it for the whole earth". The quotation indicates that he was actually writing a general geology of every part of the earth. "A fascinating view of remote times in the history of our earth emerged, although only dimly", a modern scientist has said of Steensen's treatise.

Steensen was fortunate to be living in Tuscany, which is the ancient city of Volterra every building stone and tile is encrusted with shells. An important source for the study of Steensen as a geologist, indeed, is his description of some 300 specimens of minerals and metals. Although these can no longer be identified, the description tells which material he worked on, and where he had got it. Only in one important respect was he mistaken; he had wrong ideas about the length of geological periods, speaking of thousands instead of millions of years. In other words, he employed the time intervals we apply in history.

Steensen's contribution stands out in even sharper relief when we compare his results with the ideas current in his time. Ordinary people had the strangest conceptions of many things. They firmly believed, for example, that the large boulders in fields had been flung by monsters and witches at churches that were being built, or whose bell-ringing disturbed them, and that hills were sand that had fallen from a giant's sack. Hell was located in Vesuvius or Hekla; and as for Glosspoterae, they were explained in the last chapter of the Acts of the Apostles, in the account of how Paul was bitten by a viper on the island of Melita (Malta) when laying a bundle of sticks on the fire. Everyone expected he would die, but he was unharmed; and from then on all the tongues of serpents in Malta were turned to stones and will now be found among the rocks! Accordingly, a mass of superstition attached itself to them, and they were worn as charms. But not even scientists could break away from strange notions.

Thus Thomas Bartholin and Ole Borch believed that precious stones could be excellent remedies, and the idea was widespread that fossils could grow like plants out of the soil by means of a mysterious force called Vis plastica (plastic energy). The author, A. Kircher, of a scientific work published at about the same time as De Solido argued that man and the earth were constructed on parallel lines, mountains being the earth's skeleton. He also believed that rivers came from large water tanks in the mountains that were filled from the oceans through subterranean channels, etc.

So revolutionary were - and are - Niels Steensen's geological studies that he is regarded today incontestably as the founder of the three above-mentioned sciences. It was not so, of course, from the start, and it was only at the beginning of the nineteenth century that he began to be appreciated according to his merits. Crucial to his fame was the great congress of geology at Bologna in 1881, attended by about a thousand scientists. In the present century - and especially after the Second World War - numbers of books and papers about him have been published. The biggest contribution has been a complete scientific edition of everything he wrote, in six very large volumes.

One of Steensen's acts as a geologist was a journey in the summer of 1671 to some remarkable grottoes at Gresta, not far from Lake Garda and Moncodeno on Lake Como. These grottoes always contain ice, and Steensen had been assigned by the Cimento Academy to investigate whether the controversial antiperistatis theory was correct. This had been propounded by Aristotle, and its idea is that nature concentrates forces in order to resist onslaughts by contrary forces. For example, the hot lava inside a volcano is a counterpoise to the snow on the summit. The fact that a cellar is warm in winter and cold in summer is due to antiperistatis.

Steensen found it easy to prove that the theory of nature's contrasting phenomena was mistaken. The cold air of the grottoes could not possibly come from the ice, and that could not possibly originate as a contrast to the heat of summer. Steensen reported his visit to the two grottoes in a couple of letters to Grand Duke Cosimo III, who had succeeded his father Ferdinand II that year. The letters can be used as at guide to some of the most beautiful regions of the earth to this day.

In December 1667, Steensen received a summons from Frederik III to return home, with the promise of an annual salary of 400 rigsdaler. But the recall seems to have been suspended, apparently because news had reached Copenhagen of his conversion. On 7 November, Steensen had been officially received into the Roman Catholic Church, and on 8 December - the day the letter arrived from the Danish king - he received the sacrament of confirmation from the apostolic nuncio in Florence, L. Frotti. But shortly before Christmas 1671 came a renewed summons "from him whose intimation the laws of nature and his great benefactions to me and my family bid me follow", that is the Danish king; and with this Steensen was interrupted - forever as it turned out - in his geological studies. It was his childhood friend Peder Schumacher, now ennobled as Griffenfeld, who had urged his return, as he wanted a resumption for Steensen.

It was a difficult choice for Steensen. He had the best conceivable working conditions in Florence, the mild climate and attractive scenery of Italy appealed to him, as did, even more the fervent religious life and the many venerable shrines. In his dilemma, he consulted the grand duke, who in a very cordial letter left him free to decide for himself. "Your understanding and wisdom, better than any other’s, will know how to make the right decision" he wrote, and "I can assure you of one thing, that I set as great store by you wherever you are, and that I will always cherish the same affection and the same friendly feelings towards you as have moved me to attach you to my court". Steensen decided to follow the Danish king’s summons, but promised Cosimo that he would return after a few years and become tutor to the grand duke’s son, Ferdinando.

Steensen arrived back in Copenhagen on 3 July 1672, and for two years was again an anatomist. He lodged with his sister Anne in their old home, where her husband Jacob Kitserow had carried on the workshop with great proficiency. There were children in the house, and they had bought a garden in the neighborhood with a gatehouse and six dwellings where Steensen several times performed dissections. Many a thing had changed in his native city and the fortifications the young Christian V caused to built attracted the geologist’s attention at once by the piece of amber which had been found and from which Steensen deduced marine deposits beneath Copenhagen.

But geology was not the sphere Steensen was to work in. With great enthusiasm the Royal Anatomist, as he was called for want of another title, immersed himself in his dissections to which the chancellor himself, Peder Griffenfeld, suppled rare material like reindeer and bears. On 8 February 1671, a large public dissection began in the Theatrum Anatomicum which lasted till 18 February and may be regarded as a sort of official introduction to Steensen's teaching work. He announced here the main general directions of his work, arriving at, a full clarification of the relationship between science acid religion.

The fact that this introductory lecture - by far the most valuable, and humanly one of the finest, things that he wrote - actually spelt the end of this brilliant natural scientist’s career sheds a melancholy light on its profound ideas. The evil-smelling object of dissection (an executed woman whom the headsman had supplied for the prosector) - "the cruel image of death", as Steensen put it - he used for a homage nature and to illustrate the beauty of the perception of truth. Steensen's lecture - and entire work - filled many people with sincere delight, students as well as doctors and professors. Several poems have survived which pay tribute in the manner of the time to the returned anatomist, who explains "the structure of the heart and the whole earth", and whose fame is compared to that of Alexander the Great.

Yet the sojourn in Copenhagen was on the whole a disappointment, and the other papers he wrote there are no match for his previous ones. Despite the fine title of Royal Anatomist, his position was difficult and altogether insecure. The whole summons consisted only in permission to live in Copenhagen, receive a small salary and for the rest perform private anatomy in private houses. The supply of dissection material was haphazard, and one senses behind all this the mistrust with which he was regarded, as a Catholic, in most circles. Nor was the fear of his religious influence on his surroundings altogether unfounded.

It is known, for example, that a student, J.T. Atke, made an attempt to reconvert the highly admired prosector to the Lutheran confession, but that the student himself converted to the Catholic church, left Denmark and ended his life as a Jesuit and a field chaplain to the Imperial army at Grossvardein. Steensen was also involved in a controversy with the headmaster of the learned school of Herlufsholm, Johan Brunsmand, the author of the century's history of witches. The occasion was Brunsmand’s book The Despair of Frans Spira which describes the mental agonies of an apostate, and was sent to Steensen by the author. Steensen responded with a brief exposition of the Catholic doctrine of justification by faith.

Such controversies will scarcely have been to Steensen's taste, but neither are they likely to have had any decisive influence on his decision, in the spring of 1674, to return to Italy, where they were well informed of all this. On 5 June, he submitted his resignation to Griffenfeld, revealing, among other things, that there had been no opportunity at all for dissection in the second year. He had already thanked the grand duke on 29 May for the renewed invitation to become his heir's tutor. His passport is dated 14 July 1674. On his way back to Italy, Steensen continued to work on anatomy, when, at the invitation of Duke Johann Friedrich of Hanover, he demonstrated the circulation of the blood, as well as the structure of the heart, in several dissections at the court.

At the duke's dinner table, however, he was at least as much interested in religious discussions with the courtiers and town preachers; and when Johann Friedrich presented him with his portrait on a costly gold medal with gold chain, his guest begged permission to convert the ornament into money for the poor. At the end of 1674, Steensen was back in Florence, beginning at once to teach and educate the 12-year-old heir, the later Ferdinand III, who was to learn philosophic christiana; that is to say, about both natural science and the moral-religious duties of a ruler. When the tuition ceased two years later, Steensen left to his pupil a Trattato di morale per un principe, which, however, has not survived.

At about the same time as his return, Steensen must have made the definitive decision to conclude his work as a scientist and devote the rest of his life in thanksgiving to God, to whom he always felt that he owed everything. His theological attainments were so highly esteemed by ecclesiastics that an apostolic dispensation exempted him from the obligatory examination. The conditions imposed on himself by Steensen were stricter, as indicated, inter alla, in his ascetic notes from that time. On Easter Day in April 1675, he conducted his first mass in SS Annunziata, the church that was so dear to him from the days of his conversion, and he was soon in S Gaëtano a popular and esteemed confessor with an exceptional gift of winning and guiding souls.

Nothing has evoked so many misconstructions as Niels Steensen's religious life: conversion to the Catholic Church, his farewell to natural science and, in his last years, the rigid asceticism. On the other hand, nothing has moved people, often the same people, more deeply than the great discoverer's Christian personality. A typical example is that of the chamberlain Jřrgen Wichfeld. In his book Nogle Erindringer om den danske Videnskabsmand Niels Steensen (Some Recollections of the Danish Scientist Niels Steensen, 1865), Wichfeld dissociates himself from Steensen because "at a relatively young age he abjured his forefathers' faith and finally, in obscure renunciation of all the amenities of life, abandoned himself to the service of a foreign church", yet the next moment exclaims: "A purer soul never walked the earth; everything corporeal and earthly was alien and indifferent to him - science and the higher intellectual interests, everything".

Steensen's ethical-religious aspiration is strongly defined already in the student's Chaos manuscript. He accuses himself before God for presumed waste of time; he will not participate in derogatory talk about colleagues; he resolves of the family he will some time found that religious prayer and song shall characterize its everyday life, and that the poor shall be invited to his table. One notes an exceptionally profound motive for his exact research: "They sin against God's greatness who will not contemplate the works of nature itself but, content with reading other men's books, invent and fabricate all sorts of imaginings".

Steensen's faith in Providence is so strong that it shapes not only his life but also the course of his studies. He made it a rule, he says, to do every day what he considered most fitting as regards time, place and energies, and for the rest to live so unconcerned about the future that neither by prayers nor by gifts would he seek to achieve honor or positions, or allow others to do so for him. Experience encourages him, he confesses, time after time to address the following prayer to God: "Thou, without whose intimation not a hair falls from the head, not a leaf from the tree, not a bird from the air, not a thought escapes from the mind, not a word from the tongue, not a deed from the hand, thou who leadest me hitherto by unknown ways, lead me now along the paths of grace, seeing or blind".

Actually, we owe to his submissive belief in Providence the wealth of discoveries made by Steensen, since it was his fate, he says, that continually new works prevented him from completing the previous ones: the study of the body's glands had to give way to work on the wonderful structure of the heart; a colossal shark from Livorno precluded a detailed description of the muscles, his recall in 1668 to geological studies. He saw a higher guidance in these occurrences, and reflects: "From where all this may come I will not anxiously inquire; maybe I ascribe to myself that which is due to a higher cause. Even though by long reflection I might have added something of my own to the discoveries that are not my own, I would surely, if I had gone on very long to improve upon a single discovery, have obstructed my own way to making the others".

Steensen's cautious remark about what may be due to a higher cause must be set against his statements elsewhere, where he is in no doubt that it is the guidance of God. The scientific is thus closely bound up with the religious, and he is sure that new scientific advances cannot conflict with religion and faith; on the contrary, one might say. Scientific research is simply a part of his faith: first medical, later geological, finally philosophical and theological. Consequently, he can always fearlessly submit his scientific results. It would be easy to pick out words like these from the whole of this research period and about each of the subjects of his research: "When a single feature of the human face is so beautiful and captivates the beholder so intensely, what beauty would we not see, what joy would we feel, if we could look deeply into the wonderful structure of the whole body, and thence to the soul, which so many elaborate instruments obey, and to the dependence of all these single parts on that cause which knows all that we do not know". One feels "as it were, his whole soul vibrate in these utterances", an enthusiastic Dane has said.

Steensen expressed his whole outlook best - and most finely - in the introductory lecture at the Copenhagen Anatomical Theater in 1673, in perhaps the most famous words that he wrote:

Pulchra sunt, quae videntur
(Beautiful are the things we see)

pulchriora quare sciuntur
(More beautiful what we comprehend)

longe pulcherrima quae ignorantur what
(Much the most beautiful what we do not comprehend).

There has been some argument about the meaning of the third element. It has been understood as the part of science not yet elucidated; but it can also be interpreted as the world of God, inaccessible to man. Steensen may have implied both meanings; but what is certain is that the essence is the divine. The point of the whole quotation is that in the first element he has in mind the beauty we perceive through pure senses, in the second science, in the third the world of religion (our relationship to God). Thus in a three-part formula, equally perfect in phrasing and content, one of Denmark's great sons succeeded in telling his contemporaries and posterity what he believed was the meaning of human life.

It is characteristic of Steensen's conversion that the way was not, at least not at first, through confessional discussions, which so often fired men's minds in those days, but through his generally open-minded and fervent interest in religious life; and it was great surprise to him to meet Catholics whose Christian life was quite different from that envisaged in Denmark. It emerges from his letters that he met several of them before going to Italy. Thus a Jesuit father in Cologne captivated him by referring to heroic Catholic sanctity. In Paris, he looked up the cloistered Madam Rantzau; and in Thevenot's house he discussed spiritual problems with the pious niece of his patron, saying about her later that she prepared him by her intellect and piety for his subsequent work.

But it was not until Italy that Steensen came under strong Catholic influence. Already in June 1666, he experienced something which caused his religious ideas suddenly to intensify, to such an extent that one may speak of an acute crisis. In Livorno - as mentioned earlier - he witnessed the feast of Corpus Christi. A big procession passed through the streets, priests walked with opened books, the host was carried high above the crowd, flowers were strewn on the road and the multitude bowed reverently before the sacred object. It was all bound to make an impression on a Protestant Northerner.

The question of the Eucharist, which up to then had been for him only theory, here became reality, for "either this host is a simple piece of bread, and they are fools who show it so much reverence, or the body of Christ is contained therein, and so why do I not venerate it?" One senses in Steensen's either/or the need for a decision; "I was", he writes in the same letter about the experience, "forced to say one or the other". "In such a state of doubt", he goes on, "I arrived in Florence; and the decision was made there". At the same time as he was founding new sciences, he was embarking upon a thorough study of the Christian faith. He would not just discuss the religious questions with scholars, but "I would also inform myself in all quietness, by means of the original witnesses of the Scriptures and the oldest authors, especially the ancient Greek and Hebrew manuscripts - I had learnt these two languages in earlier studies".

It is characteristic of Steensen that in making important decisions he is very slow; it is as if they have to ripen of their own accord, and no pressure of any kind has to be exerted on them. These studies will unquestionably have meant much to him, but association with good friends will have meant more; for when telling of his conversion to Catholicism later on he emphasized the view that devout Catholics who had read his scientific works wished to make his acquaintance. That is how the first contact came about, and he saw in it the hand of Providence.

In particular, two pious women influenced him. He found in them a practical Christianity acquired through experience. One of the women was an elderly nun of high birth who had charge of the small pharmacy of the Annalena nunnery. Her name was Maria Flavia, and Steensen bought his medical requirements from her. The old sister had lived a long life of charity and was not long in finding out that he was not a Catholic; and she spoke to him about it. Discovering that he was a quester, prepared to listen to her arguments, Sister Maria was doubly ardent, and got so far as to persuade him to offer prayers that she taught him in order to achieve the right faith, as well as to fast, and at her suggestion he visited the pilgrim church of SS Annunziata in the city.

But as he continued to delay making any decision, she referred him, in the spring of 1667, to talks with one of the city's noblest ladies, Lavinia Cenami Arnolfini, wife of the minister of Lucca at the Medici court. She lived a happy married life with her husband and children, and was by nature devout; a gentle and at the same time strong personality, who knew how to conduct herself in the most natural manner in the highest circles, as the position of diplomat's wife required of her. Generous to the poor, she was not above nursing the sick when that was necessary; she was thus an "active" Christian, as Steensen was later to call his "mother in Christ". In her conversations with him she had good support from her learned confessor, Father Savignani, as he possessed the scholarship she herself lacked, but which in discussion with Steensen was a necessity.

One day, during a visit to the diplomat's home on the banks of the Arno, when he frankly declared that despite of every sympathy for the Catholic church he knew of no motive that would make him desert the religion his birth and native country bound him to, the lady exclaimed impulsively: "Oh, if my blood could but convince you how necessary this is, I would, by God, at this moment give my life for your salvation". In a book about her, it is said of her friendship with Steensen: "She shed her tears daily for God, and undertook special penances in order to move the divine clemency to enlighten his spirit. She prayed to God for the light with which in their conversations she continued to press like a goad into Niels Steensen's heart; and when the confessor attacked him with reasons, she urged him with her burning zeal, her love and her example".

At last, on All Souls Day, 2 November 1667, the decision was taken. At noon, Steensen had a long talk with Lavinia Arnolfini, and it ended with her growing impatient and indeed angry. "Signor", she said, "the visits and the conversations I have permitted you entirely against my custom had no other reason but impatient zeal for your eternal salvation, and have been only a struggle of love to win you for the faith. But since you yourself have not the will to arrive at the recognition of truth, I should not be wasting my time to no avail. So do not come to me any more unless you have decided to become a Catholic".

After this parting shot, one can imagine the state Steensen was in when he walked the old streets of Florence. Eventually he happened to meet Father Savignani. The priest had no idea of what had happened, believing that, as usual, they would engage in discussing theological problems. So he told Steensen that he would go and get some books. When he returned, Steensen was transformed; all doubt had gone. When Lavinia Arnolfini was told, she hurried to the chapel to sing a Te Deum Laudamus. In fact, she had begun to regret her - as she thought - unkind behavior to Steensen; but she was sure now that God had used her to convert him. The Catholic form of Christianity now stood out for Steensen as a truth as strong as scientific recognition.

One may hazard a guess that Steensen's intense internal struggle before conversion was connected most of all with a presentiment that his religious life would soon beset a mind like his wholly and completely, leaving no room for anything else. At any rate, the archbishop of Florence, Father Nerli, testifies that immediately after his conversion Steensen, seeking to scale the steepest heights, and although a guest at one of the grandest ruling courts of the Baroque period, at once made the promise of evangelical poverty. A natural consequence of Steensen's new outlook was an urge to give it practical effect. He would therefore prepare himself for ordination. Everyone who knew him personally agreed that such was his life that scarcely anyone could conceivably be more worthy of ordination. "Believe me, Signor Nicolaus is truly an angel in his ways", one of his Italian friends says. Another declares that "his goodness and his virtues are so bounteous that I rank him equal to the holiest of men".

It was actually science that made Steensen give up science! When the celebrated polyhistor Athanasius Kircher a few months after his ordination at Easter 1675 expressly inquired the reason for it, Steensen replied: "Indeed, when I tried to form a picture of God's benefactions toward me (I would never be able to do so adequately) I found them so great that I felt the deepest desire to proffer my best for him, and in the best way. Recognizing the value of the priesthood, which offers thanksgiving for daily benefactions at the altar, atones for sins and renders other services pleasing to God, I asked for and was granted permission for me and for others to make the pure unblemished sacrifice to the eternal Father". Steensen's rich life - not least his life of enquiry - thus wanted to ring out as a thanksgiving to God.

During the first two years after his ordination, Steensen did not hold any clerical office as such but served chiefly as tutor to Cosimo III's son and heir Ferdinando. Taking advantage of this position, he directed the grand duke's attention to one of the state's greatest problems, warning him of the heavy burden of taxation on the less well off, who found it quite impossible to better themselves. While unable, perhaps, to abandon altogether his geological studies, he devoted himself increasingly to theological ones. Many of his theological works are polemical pamphlets, naturally so since he came under fierce attack from Protestants in Holland, Germany and Denmark.

Steensen felt that he had to defend himself, and equally that he gained greater clarity over his own position by participating in these polemics. Writing to a lady of human judgment and discernment, he said: "One can act from three kinds of motives: as an ape, as a pagan philosopher or as a Christian. The one who is content with the purely sensual things imitates the knowledge and behavior of the chimpanzee, which, to be sure, is more inquisitive than any other animal and imitates what it sees others do". Steensen's old teacher and friend Ole Borch must have urged him to revert to Lutheranism. His reply concludes with an appeal to faith and love: "May we, dear Lord, strive that all will reject the vanity and falseness of the world and with one heart and one mouth and one faith love God. What joy would this be to us in eternity if we serve him alone and get sinners to abstain from all wickedness and perform only the works of God. Thou hast broken my chains, Lord; I will bring thee the offering of praise, and I will invoke the name of the Lord".

Soon, however - as unexpected as it was undesired - the call would come from an entirely different direction. The brother of the Danish queen, Sophie Amalie, Duke Johann Friedrich of Hanover, wanted Steensen, in 1676, as the bishop in his city. The duke had converted to the Catholic faith after a visit to Assisi, and there was a small congregation in Hanover, an almost purely Protestant country. The year before, Johann Friedrich had appointed another great man of the period, the famous philosopher Leibniz, as his librarian, and it is highly likely that it was Leibniz who, knowing Steensen personally, had suggested him as bishop of "the Northern missions". Steensen himself suggested that the duke should rather consider others for the post of prelate, but declared himself ready to go to Hanover as an ordinary priest. "That seems to me to be the work which God above all wants of me", he wrote, although he would leave it to the duke, and in the last resort the pope, to decide the matter.

Innocent XI gladly agreed to Steensen's appointment as bishop, and so, to general regret in Florence, he left that city in May 1677, on foot, and as a pilgrim intending to live on alms, for Rome, there to spend four months devoted entirely to preparing himself for the new office. Humbly, and quite convinced of his unworthiness, he wrote to one of his devout friends asking him to beseech the divine Majesty to enable him to discharge, to human eyes, the honorable office that in the eyes of God was an appallingly heavy burden. "That it will be a consolation to me in the hour of death, to the honor of God in all eternity and the joy of you and all God's friends". After his consecration as bishop, Steensen quickly departed for Hanover. He left Rome on 27 September, going first on horseback to Florence in order to take leave of his friends there. Then, crossing the Alps by mail coach, he took ship from Frankfurt for Cologne, arriving in Hanover in November 1677.

Steensen had plenty to do in his new office. Besides writing several theological pamphlets and many letters, he cared for his small congregation, and over a hundred people converted to the Catholic faith under his influence. Many of the city's Catholics being foreigners, he preached not only in German but also in French and Italian. There were many duties, as he was the bishop for the whole of north-west Germany and Denmark/Norway. He described the situation in Copenhagen as the most favorable since the Reformation, thanks to the Catholic resident whom Johann Friedrich had sent to Denmark; and in Norway in 1678 the first mass held since the Reformation.

In his dealings with people of a different faith Steensen combined clarity with mildness, and Hermann Conring, the founder of German legal history, called him an anatomist who had become an "orthotomist", a good tailor of the truth. The closing words in his paper directed against the Danish professor Nold reveals Steensen's disposition: "I have published my thoughts about faith without hatred of anyone" he says; and he invokes God as a witness that he was ready to choose the most perfect ways to God's love wherever he saw them, "even if I had to spend the rest of my life in affliction, ignominy and misery". One of the most interesting aspects of the two years of Steensen's stay in Hanover is his relationship with Leibniz, the philosopher and librarian, who occasionally attended his services. Leibniz set immense store by Steensen as a scientist.

He especially admired De Solido with its many scientific results, and he imagined that by further studies Steensen could draw conclusions "regarding the origin of the human race" and "find other fine truths that can confirm what the Gospels tell of". In all this, however, Leibniz was disappointed; Steensen was too deeply involved with his relation to God, nor could he go along with Leibniz when they discussed contemporary attempts to unite the divided church after the many wars of religion. They might agree on the end, but not on the path. Leibniz recommended a reunification of the churches, but Steensen could not agree to an outward union without having at the same time full agreement on the most essential questions of faith.

As with Spinoza before, Steensen missed in Leibniz full religious certainty. Only when a common basis of faith had been clarified could there be any question of uniting the churches. Steensen actually reproached Leibniz for his blurred approach with the cautioning remark that "he is nowhere who would be everywhere". Despite Steensen's harsh criticism, however, the religious endeavors of Leibniz have to be acknowledged, and his motto "Science must serve life, and life God" was in no way an empty phrase. For the rest, Leibniz was firmly convinced of the honesty of Steensen's conversion to Catholicism; it had, he said, occurred "after mature reflection and after a thorough study of old and new writings".

On one of the last days of 1679, Johann Friedrich died suddenly during a journey to Italy, and was succeeded by his Protestant brother, Duke Ernst August. Although both he and his wife, the gifted Sophie of the Palatinate, had been kindly disposed to Steensen from the start, there was no longer any place for him at the court, and a discussion now began in church circles on how he should be employed. Meanwhile, he was able in cooperation with the new duke, who behaved with great tolerance, to ensure that the Catholic service at the palace chapel could continue in the city, under freer conditions than ever before.

At this very time, the prince-bishop of Paderborn, Ferdinand of Fürstenberg, was looking round for a suffragan bishop for the diocese of Münster, whose rule he had just take over. Happening to read a letter from Steensen to his secretary, he was so struck by its zeal that he applied to Rome for the writer as an assistant. The papal bull of consent is dated 7 October 1680, but Steensen had already taken up his appointment in this see ravaged by the wars of religion in July. He was to serve there from 1680 to 1683, and was assigned a wealth of functions, especially since the prince-bishop was ailing.

Steensen made many visitations in the parishes, many of which had not seen a bishop for decades, and altogether managed to visit 200 of the 250 of them. He would often walk for 5-6 hours a day, and would frequently preach three times a day. His curate has recorded that "his words convinced not only by their reasoning but also by their temperance", and "he displayed great dignity and extreme modesty in all his conduct". Besides being bishop, Steensen was also the parish priest of a congregation of some 2,000 people, and the social suffering he found in many places made a deep impression on him. His first winter in Münster was so severe that he personally became an outspoken beggar for the poor at the prince-bishop's. Writing in a letter of three small boys who had to sleep in the open every night, he says: "I cannot take my eyes off these people who thus live in the severest and most extreme distress; and although I have incurred debt out of charity for the poor, I have instructed the curate by no means to allow them to sleep out in future".

Steensen's greatest concern, however, was the renewal of the priesthood. There was a shortage of zealous priests, for one thing because the benefices, especially the most important and most remunerative of them, were reserved to the families of the nobility, who found their support in the chapter. Many of these families had done well out of their forefathers' faith but, as Steensen rightly saw, their disposition was composed of "spirit and flesh". Opposition to them was by no means the only result of Steensen's endeavors. The prince-bishop, the humanist Ferdinand, who had first exhorted Steensen not to be too strict and ascetic, put steadily increasing power into his hands, and it is clear from reports to the pope how much emphasis Steensen placed on getting the right men appointed to offices. The sharpness of the pronouncements is exemplified in one of his observations on some officials, where he says that "many girls and old women have more understanding of pious practices than they have". Abbeys were also chastised when he discovered instances of gross neglect. Nor did he stop at punishing or dismissing unworthy office holders.

Steensen's views on what a priest or spiritual adviser should be like finds expression in a short book he published in 1684 with the title Pastoral Duty. The purpose of the publication is explained on the title page thus: "How the spiritual adviser, by putting everything else aside, should think of being perfect if he is to lead the sheep that are entrusted to him to eternal salvation. The priest's first duty is to be a model; the second to understand the art of studying the secrets of the heart, which are often concealed by people themselves. By means of this art he will discover the inmost nature of people, and thus will know how much is missing. It is a matter of saving souls, and so a priest must be more alert than a ruler's adviser". From this it will be understood that Steensen laid great stress on spiritual care of the individual. That this should be so is indicated by many of the parables of Jesus.

In a major section of this little book, Steensen compares a priest with various other people: a gardener, a general, a doctor. The comparison with the last named seems very modern. A doctor must know each single patient if he is to cure illness. As there is an almost endless profusion of illnesses and medicines, one must prescribe this medicine for one person, that for another. In the case of some one must apply the knife, even fire. In the same way, spiritual illnesses are numberless, and the same remedy will not cure all. When, therefore, a priest would discharge the task of a doctor of the soul, he must know each one's spiritual illness as thoroughly as possible as regard symptoms, causes and their corresponding remedies. We have a pattern in Christ, who says he is come to heal the sick, and has actually healed each one in different ways. Niels Steensen's words were written 300 years ago, when the science of psychology was still undiscovered.

When Ferdinand von Fürstenberg died in 1683 and a new bishop was to be chosen, Steensen was involved in a close struggle with the chapter. The most influential members thought first and last of themselves, seeking to obtain as many benefits as possible, and it soon turned out that the elector and archbishop of Cologne, Maximillian Heinrich of Bavaria, was the chapter's candidate, although he already held the archdiocese of Cologne and the dioceses of Lüttich and Hildesheim. His candidature was promoted by large sums of money, promises and threats, and Steensen became increasingly convinced of the un-churchlike character of the coming election.

When approached with a request that he should conduct a mass to the Holy Spirit before the formal election the next morning, he therefore refused, pointing out that the bishop had already been elected without the mediation of the Holy Spirit. In reality almost powerless, he now saw no alternative but to leave the city. He went to Hamburg, in order to discharge a bishop's duties again for northern Europe (he had asked to be excused from this in the Münster period), and he kept this office until his death. He had not given up the struggle altogether, however, and in a new report to the pope, who like the emperor in Vienna was on his side, he spurned the objection that an accumulation of power in Catholic hands was a political necessity. In the light of his three-years' experience he believed, on the other hand, that it led to greater secularization and loss of respect. "One Francis of Assisi and one Ignatius de Loyola", he said, "have won the Church more power and honor in their time than the armies and treasures of all the rulers together".

It was a hard life Steensen now embarked upon. Several dark shadows were passing over Hamburg, notably a bitter struggle between the well-to-do citizens and the people's party and a disastrous fire in the summer of 1684. In addition, solidarity among the nearly 600 Catholics in the city was so poor that Steensen, who was becoming more and more ascetic, at length came to feel himself superfluous, although he worked energetically at the tasks that lay at hand. He lodged with an old friend and student companion, the Tuscan envoy Th. Kerckring, and had an annual allowance of 800 darers from Archduke Cosimo. Once, he felt the desire to dissect again. To show a friend who had begun to doubt how God's wisdom is revealed through nature he performed a dissection of a heart.

But he longed to be back in Italy, in Florence, the city where he had spent the happiest time of his life, founded new sciences, made appreciative friends and finally found the faith he felt was the right one. This is made clear in a letter to Cosimo III of July 1684, in which he writes: "In Your Highness's last letter I must read again and again the words that we may not see each other any more in this life, and it breaks my heart; it is yet my longing to see again the people and places through which God has shown me such an abundance of grace that I must at least flatter myself with the hope in my present feebleness to receive once more fresh energy and strength from the fervor of my benefactors and friends and feel the mystical influence of those shrines".

Steensen hoped, in other words, for a spiritual renewal in Italy, and after several refusals he was eventually given leave by the pope to go there. Before doing so, however, he wanted to revisit the city of his birth. To that end, he had already, eight months earlier, had a Danish passport issued, and he now spent some ten days unobtrusively in Copenhagen. Back in Hamburg, he found waiting for him a letter from the duke of Schwerin inviting him there, where there was a small Catholic congregation of a score of families. He felt it an obligation to go there and strengthen the small Catholic mission, and there he lived for the last year of his life. He would never see Italy again.

The last year of Niels Steensen's life is recalled by a young officer, Johannes Rose, in a short, vivid book that he called The Life and Death of Nicolaus Steno. Rose served in the bodyguard of the duke of Hanover, but influenced by Steensen he converted to the Catholic faith and became Steensen's disciple, loyally attending him and nursing him in the final severe period until his death.

The former officer and gentleman of the court in the account of his association with the strict ascetic tells how his household at that time consisted of two almoners and two nobles he had converted, one of whom served as his secretary, together with three servants and a kitchenmaid. He would never keep a carriage himself, but the duke used to lend him one when needed, together with two horses for town use and six for the country. He never let his servants wait on him at table, but allowed them all to eat in the same room and at the same time as himself, though at a separate table.

All the other members of his household ate at his table together with him. There were never more than four courses plus a dessert, even though noblemen from the court often dined with him. There was always reading aloud from a devotional book at mealtimes, and he would introduce each passage by a reading from the Gospels, followed by some devout pronouncement. Before they left the table, one of his two almoners would lead a short spiritual and intimate discussion. Every member of his household used to rise at five o'clock in the morning. They would take half an hour for dressing, whereupon there would be community prayers lasting for an hour. He would then read for them a few lines from The Imitation of Christ, a book he set such great store by that he always carried it with him. Next there would be mass, which he never failed to conduct every day even during serious illness, except on the last two days before his death. Communion would be celebrated later in the day, and after the evening meal before retiring for the night there would be an examination of the day's events and some hymns would be sung.

Rose also relates how Steensen lived more and more ascetically, with many fast days and plain food. He dressed like a poor man in an old cloak, which he wore both day and night, summer and winter. He sold his bishop's ring and cross to help the needy. He drove in an open carriage in a harsh climate in snow and rain. He slept for only a few hours at night, and mostly in a chair. He was reproached while he lived for these mortifications; they shortened his life, he was told, and nobody should hate his flesh. His reply to this was: "I do not hate my flesh, but subject it to the spirit so that both may become blessed. So many thousands before me have lived more strictly; why should it not be permitted to me? And because I do not do so for other reasons than love of God, I hope that in his grace he will look down upon this poor sacrifice". An aspiring mind such as Steensen's may well be tempted to "exaggeration", but his notes on the importance of self-denial contain nothing more than tested Catholic ascetic tradition. One must, he says, be like a traveller towards eternity, unimpeded by the things of this world, like a magnetic needle which always points to the sun.

We have a highly personal testimony to the workings of Steensen's mind in the confessions or notes, dating apparently from 1684, in which, in a systematic searching of his conscience, he looks back on his own life. The whole becomes an extremely self-critical evaluation of real and supposed faults, beginning with the words: "My sins always stand before me. Just Judge, for whom nothing remains hidden, nothing unatoned, who searches Jerusalem with lanterns...". What does Steensen accuse himself of? He says, for example, that he longed far too much for the publication of his works, that his opinion of the censors was too little respectful, that when travelling in Italy he refused a beggar alms, that he failed to enter an order; and in his work as a priest and bishop especially he finds many things with which to reproach himself, including his departure from Münster in protest against the simoniacal election.

The seriousness and severity of such self-critical complaints should not, however, mislead us into regarding Steensen as an obscurantist, unbalanced and unhappy man. Rose adds to his account of Steensen's mortifications that "despite everything he was so happy that his face alone inspired one with piety". Although he had a wonderful ability to conceal his penances, his fervent and happy communion with God could not be concealed, Rose says. "To the extent that I have succeeded in getting to know the outward behavior and inner life of this holy prelate", he writes, "I venture to say that his thinking about God and his life in him were almost without interruption and of the deepest intensity". This impression is confirmed by several people who knew Steensen, including J.N. Pechlin, professor of medicine at Kiel, who although deeply disappointed by Steensen's conversion said: "Yet the man's saintliness continued to shine in his life; his conversations and the letters with which once or twice he also honored me testified throughout to love, patience and a moral life which consists in the imitation of Christ".

In the last years of his life, Steensen suffered from a malignant and painful illness of the stomach and bowels, which caused his abdomen to swell visibly and finally forced him to keep his bed. But he celebrated mass right to the end, and just before he died he asked Rose to give him paper and ink so he could write to Cosimo III. In the letter, he requested the grand duke to defray the costs of his burial, which he wished to be carried out in the manner of the poor.

Steensen had asked a Jesuit father of Lübeck to come and administer the last sacraments to him, but the father failed to arrive in time. Steensen in a clear voice then made a public confession. He begged everyone humbly for forgiveness, thanked God for having led him to the church and declared himself ready to die as a Catholic Christian in obedience to it. Regarding sometimes his swollen abdomen, he said: "I wonder that I do not burst, for I cannot possibly become more swollen than I am. I suffer intense pains, my God, and I hope they will urge thee to forgive me if I do not unceasingly think of thee. When we have received the good from thy hand, why should we not receive the bad also? Whether thou will that I shall live on or that I shall die, I will, my God, what thou will. Be blessed in eternity, and thy holy will be done". He remained conscious till the end; and when he knew that death was near he had the prayers for the dying read, and Rose records that almost all the time he had "the praise of God and the name of Jesus Christ on his lips, saying "Jesus, be my Jesus" (i.e. my Savior), and I will for ever praise thy mercy".

Niels Steensen breathed his last at seven o'clock on the morning of Thursday, 25 November, 1686. When Rose consulted Cosimo about the funeral, the grand duke was never in doubt that Florence should be Steensen's last resting place, and he wanted the body conveyed by sea from Hamburg to Livorno. The coffin was enclosed in a box so the seamen would think they were carrying a consignment of books, as stated in the bill of lading. Clearly, they will have been afraid to sail with a corpse.

The burial, in the crypt of the Medici sepulchral church of San Lorenzo, did not take place until October 1687, nearly a year after Steensen's death. The body lay there until 1953. Then, in connection with the revived moves towards Steensen's canonization, the tomb was opened and his earthly remains were after some difficulty identified. As part of the very slow and painstaking process of making him a saint, it was necessary to find him an even finer burial place, in a chapel where there was also an altar. Several committees were appointed to prepare the solemn transference to the new resting place. A member of one of the committees was the Danish poet Johannes Jřrgensen, who was an honorary citizen of Assisi.

A small chapel on the right-hand side of San Lorenzo was made available and renamed Capella Stenoniana. The Italian state donated a fourth-century Christian sarcophagus that had been found in 1933 in the River Arno, having probably been washed overboard during transport to Florence. On its front are three biblical reliefs. The one on the left shows the three young men who, according to the book of Daniel, are to be cast into the fiery furnace for refusing to worship the image of Nebuchadnezzar. In the middle one, Jesus is seen taking leave of his disciples after the Last Supper; and in the one on the right, waking the daughter of Jairus.

On 25 October 1953, Niels Steensen's coffin was led in solemn procession through the streets of Florence, where thousands of people were lined up and all traffic was stopped. Danes carried Steensen's remains on their shoulders on the final stage into San Lorenzo, which was decorated with flowers and candles. The coffin was carried through the church to the sound of Bach's St John Passion and the Catholic bishop of Denmark celebrated mass. Steensen's great achievements were celebrated by Danish and Italian scholars in the Palazzo Vecchio where he had once lived.

The old marble slab was laid over the sarcophagus in the Capella Stenoniana, hearing the Latin inscription by the Dutchman Jakob Toll which reads:

Back to top