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widely known, subjects.

Friday, January 1, 2021

A boundless mind

The life of the polymath Thomas Young reminds us of the staggering potential of the human intellect.

Portrait of Thomas Young by Henry Briggs, after an original painted by Sir Thomas Lawrence c. 1822 (Wikimedia Commons).

THOMAS YOUNG (1773–1829) is mainly remembered today as the scientist who, in the early nineteenth century, demonstrated that light behaves as a wave, using his celebrated ‘double slit’ experiment. Significant as this discovery was, however, remembering Young for it alone is but an extremely poor recognition of his achievements. By the time he died at nearly fifty-six years of age, Young had not only proved that light is a wave, but, among other things, he had also demonstrated how the eye focuses on objects, discovering at the same time the phenomenon of astigmatism; he had advanced the three-colour theory of human vision, which was confirmed experimentally in the mid-twentieth century; he had invented ‘Young’s modulus’, an important measure of the elasticity of materials; and he had made foundational contributions to the decipherment of Egyptian hieroglyphs, in addition to deciphering another ancient Egyptian writing system, the demotic script. Besides these major accomplishments in physics, physiology, engineering and Egyptology, Young was also an experienced physician, a distinguished linguist and antiquarian, and a scholarly authority on an astonishingly wide variety of subjects, from astronomy and calculus to carpentry and life insurance. Rather than approaching all these subjects as a mere diversion, Young mastered and made original contributions to each of them. The extraordinary breadth of his knowledge was arguably on par with that of Leonardo Da Vinci; and it is fair to say, indeed, that Thomas Young might have been the world’s last ‘Renaissance man’.

As the writer Andrew Robinson explains in his superb biography of Young, The Last Man Who Knew Everything, Young not only enjoyed a magnificent intellect, but also possessed the attributes which we now associate with the notion of a ‘good scientist’. In doing his scientific and scholarly work, he did not aspire mainly to fame, wealth or social recognition, but rather to the pure satisfaction that accompanies the pursuit of knowledge. In fact, having been trained as a physician, Young published many of his non-medical works anonymously, in the fear that his extraordinarily broad interests might dissuade patients from attending his medical practice, opting to consult more ‘centred’ doctors instead. Moreover, his knowledge of science and his awareness of the flaws of nineteenth-century medicine precluded him from adopting the air of overconfident authority which was expected of physicians, ironically giving the impression that he lacked in expertise. Young was fanatically committed to truthfulness and transparency in his research, and was swift to acknowledge and praise the work of his colleagues and predecessors in every field he studied. Notably, he also was, in both his professional and his personal life, a distinctly modest and self-deprecating man, attaching plenty of significance to the role of chance in his career. In a letter to his lifelong friend, the antiquary and politician Hudson Gurney, he wrote: “It is well for me that I have not to live over again; I doubt if I should make so good a use of my time as mere accident has compelled me to do”. In Robinson’s words, “Young was keen on the idea that what one man had done, another man could also do; he had only a small belief in individual genius”.

Born in 1773 into a large Quaker family in Somerset, England, Young soon gave early evidence of his intellectual voracity: he could read fluently by the age of two, and before he was four he had already read the Bible twice. As a schoolboy, he learned Greek, Latin, French and Italian, and he independently went on to tackle Hebrew, Arabic, Persian, Chaldee, Syriac and Samaritan, developing a familiarity with languages that would prove invaluable in his adult research. With the assistance of some neighbours and family acquaintances who were appreciative of his precociousness, he also built telescopes and microscopes and conducted chemical experiments. Even at this early age, Young had a clear ambition of mastering as many areas of knowledge as he could reach; and, even more remarkably, such curiosity and determination would not abandon him until his dying day. As the majority of child prodigies, he acquired most of his knowledge directly from books: in a letter to his brother, he remarked that “Masters and mistresses are very necessary to compensate for want of inclination and exertion: but whoever would arrive at excellence must be self-taught”. Perhaps one of his most impressive feats as a boy, besides his study of dozens of languages, is the fact that, by the age of seventeen, he had studied Newton’s great scientific treatises, the Principia and the Opticks, in full depth — and there is evidence that he was able to follow their advanced mathematics. This showcases the extreme versatility of mind that would characterise the adult Young; as the writer Isaac Asimov noted, “He was the best kind of infant prodigy, the kind that matures into an adult prodigy”.

At the age of nineteen, Young moved to London in order to being his medical training at one of the city’s private anatomy schools. There, after a dissection of an ox’s eye, he became interested in the process by which the eye focuses on objects located at different distances, known as accommodation. He read all the previous literature on the subject, including the theories of Johannes Kepler and René Descartes. The former had proposed that accommodation is effected by the movement of the crystalline lens (the lens found inside the eye) back and forth along the horizontal axis of the eye, just like the lens of a camera. Descartes, in contrast, had argued that the crystalline lens is fixed, and that accommodation occurs not through its movement, but through a change in its shape. Young’s examination of the ox’s eye led him to conclude that Descartes’s theory was correct, and that the crystalline lens was able to alter its own curvature because it was muscular. This work soon led to Young’s first scientific publication, a paper titled ‘Observations on Vision’, which was read to the Royal Society of London by his great-uncle, the physician Richard Brocklesby, and published in the society’s Philosophical Transactions when Young was still nineteen years old. Today, we know that Young was right in concluding that accommodation occurs through a change in the curvature of the crystalline lens; but the latter is not, in fact, muscular, as he then claimed, being instead surrounded by a set of radial muscles which effect the deformation.

Diagram of the parts of an ox’s eye from Young’s first article (Young, 1793).

The following year, Young was elected a fellow of the Royal Society, one of the highest scientific honours in Britain. Although his work on vision was certainly extraordinary for someone his age, it should be borne in mind that the standards for admission into the society were less strict at the time. As Robinson notes, “It is inconceivable today that even a young man as gifted as Young could be elected a fellow of the Royal Society on the evidence of one scientific publication”. Despite his appreciation of this honour, Young’s lifelong shunning of official titles is patent in the letter where he informs his mother of his election: “I hope I am not thoughtless enough to be dazzled with empty titles which are often conferred on weak heads and on corrupted hearts”.

At the turn of the nineteenth century, university degrees were increasingly important for trained physicians to distinguish themselves from quacks and charlatans, which were not in short supply in London. Hence, in spite of having no special interest in attending university, Young went on to study medicine at the universities of Edinburgh, Göttingen and Cambridge. Driven by his multifarious interests, however, he also took the opportunity to improve his knowledge and skills in plenty of domains other than medicine; writing from Edinburgh to his mother, he made clear that he “by no means wish to confine the cultivation of my mind to what is absolutely necessary for a trading physician”. While in Edinburgh and Göttingen, Young made the acquaintance of classical scholars and took lessons in music, drawing, dancing, flute playing and horsemanship. In 1796, after a total of four years of training, he defended his thesis in Göttingen and became a doctor of medicine. Nevertheless, upon his return to England he discovered that he did not yet qualify to be a licentiate of the Royal College of Physicians, which now asked candidates to have studied for at least two years at the same university. Since Young had not spent enough time in either Edinburgh or Göttingen, he was forced to return to university for another two years. He chose to pursue the degree of bachelor of medicine at Emmanuel College, Cambridge. As he considered the ancient university to offer him little in terms of medical training which he had not already acquired, he spent most of his time reading, writing and carrying out experiments in his college rooms, as well as making the acquaintance of a variety of scholars from across the university. He certainly did not go unnoticed in Emmanuel College, although few fellows were pleased to meet a student who was able to challenge their knowledge of their own disciplines.

Young returned to London in 1800; now finally able to practice medicine, he opened a private practice and started to look for a consultant position at a hospital. Crucially, he had received a considerable inheritance after the death of his great-uncle in 1797, which alleviated his financial dependence on patients, thus allowing him to extend his earlier research on vision. In a lengthy paper titled ‘On the Mechanism of the Eye’, read to the Royal Society in 1800, Young conclusively established how the eye focuses, and also diagnosed and measured astigmatism for the first time — in his own eyes. To achieve this, he first improved an existing instrument for measuring the focal distance of an eye, known as an optometer. He then performed an extremely ingenious — and sometimes disturbing — series of experiments to ascertain whether the eye alters its length or its curvature during accommodation. To discover if his eye’s length changed, he inserted the ring of a metal key into his eye socket, and fixed it against the back of his eye: “The key was forced in as far as the sensibility of the integuments would admit, and was wedged, by a moderate pressure, between the eye and the bone”. In this position, the pressure of the key against his retina caused him to see a bright spot, or ‘phantom’; even a slight change in the eye’s length, he argued, would modify the pressure against the key, and hence the size of this phantom. In this way, he showed that the eye does not alter its length when focusing on objects at different distances. To see whether the eye changed its curvature, he closely examined the shape of a candle’s reflection on another person’s cornea, concluding that the eye’s curvature was also unaltered during accommodation. Finally, to verify that it was the shape of the crystalline lens itself that mattered, Young used his optometer to test the power of accommodation of five people whose crystalline lens had been removed as a treatment for cataracts. This showed that “in an eye deprived of the crystalline lens, the actual focal distance is totally unchangeable”: people without a crystalline lens could not focus their eyes on objects, and needed to use a series of spectacles for looking at objects at different distances. Nevertheless, Young was careful not to reiterate his earlier hypothesis that the lens itself was muscular, of which he was no longer convinced. In fact, the ciliary muscles that cause the crystalline lens to change its curvature would not be discovered for several decades.

Illustration from Young’s second paper on vision, presenting different images as perceived by the author himself during his experiments (Young, 1800).

In addition to his experiments on the eye, Young immersed himself in an investigation of the nature of light, which would lead to his defence of the wave theory of light in two papers read to the Royal Society in 1801 and 1803. In the early nineteenth century, the leading theory of light was still Newton’s ‘corpuscular’ theory, which proposed light to be a stream of particles that move in straight lines through empty space. Competing against this was the ‘undulatory’ or wave theory of the astronomer Christiaan Huygens, according to which light was a wave that spread through an invisible medium known as the ether. Both theories were equally capable of explaining the reflection of light on surfaces; the corpuscular theory, however, was more successful at explaining the rectilinear propagation of light, while the wave theory was better suited to explain refraction (the bending of light rays when passing from one medium to another).

Young’s means for conclusively demonstrating that light behaves as a wave was a phenomenon known as interference. This is easiest to picture using the example of waves in water: if two stones are dropped simultaneously on a quiet pond, they produce two sets of waves on the pond’s surface, which cross each other as they spread. At the points where the crests (or the throughs) of two waves coincide, their effects reinforce each other to produce a higher crest (or a lower trough); while at the points where the crest of one wave coincides with the trough of another, their effects cancel each other and the surface remains level. These two types of interaction are called constructive and destructive interference. Young realised that, if light were a wave, the interference between two light rays would produce an alternating pattern of light and darkness. Such a phenomenon, where light added to light can result in shadow, would be impossible to explain for the corpuscular theory. In a bold leap of intuition, Young went on to propose that the colours of light correspond to waves of different frequency (or wavelength); this immediately allowed his principle of interference to explain the puzzling iridescent colours emitted by certain objects, such as soap films and some insects’ wings. In his 1803 paper, Young presented an experiment where he directed a beam of light through a small aperture, and then split it into two beams using the edge of a card. Although this was not yet his celebrated double-slit experiment, it showed that the interference between the light rays passing through each side of the card gave rise to parallel fringes of light and shadow on a screen. Due to the enormous weight of Newton’s theory, however, few people accepted Young’s conclusions in 1803. Despite this, he was confident of his work; in a letter to a friend, he wrote: “The theory of light and colours, though it did not occupy a large portion of time, I conceive to be of more importance than all that I have ever done, or ever shall do besides”. Indeed, his demonstration that light behaves as a wave is considered to be his most significant contribution to science.

Diagram illustrating the interference between two sets of waves in water, produced using a device of Young’s invention known as a ripple tank (Young, 1807).

Young’s adherence to the wave theory of light, in turn, led to his second major contribution to the understanding of vision: his theory of three-colour vision, advanced in his 1801 paper. In this case, his proposition was closer to a powerful intuition than to a formal theory. It had by then become established that the palette of colours in light was derived from a small number of so-called primary colours, possibly three or five. Young’s breakthrough, derived from his association of colour with wavelength, was to imagine that the brain could perceive light using three distinct types of ‘receptors’ in the retina: one receptor for red light, corresponding to a long wavelength, another for yellow light, with a middle wavelength, and a third for blue light, with a short wavelength. Intermediate colours (with intermediate wavelengths), such as green, would stimulate two types of receptors to a similar degree, resulting in a composite signal which the brain would interpret as green. In this way, Young implicitly advanced the first theory of vision which suggested that the brain not only receives information, but also processes it in order to generate the sensations that we perceive. This idea is one of the cornerstones of modern neurology, proving just how far ahead of his time Young’s intellect was. In fact, Young’s three-colour theory remained entirely forgotten until the 1850s, when it was rediscovered by the physiologist and physicist Hermann Helmholtz, who developed it into a full-fledged theory that would later be extended by the physicist James Clerk Maxwell. It was only in 1959 that two groups of scientists in the United States experimentally demonstrated that colour is perceived through three kinds of receptors which cover the retina. Notably, Young even went as far as to suggest, correctly, that colour blindness is caused by the dysfunction of one of the three types of receptor.

In the period between 1801 and 1803, Young not only worked as a physician and investigated light and vision, but he was also a public lecturer at the Royal Institution of London, where he was appointed professor of natural philosophy in 1801. In fact, this period was possibly the most strenuous in Young’s life: in 1802, he wrote to a friend that “an immediate repetition of the labour and anxiety that I have undergone for the past twelve months would at least make me an invalid for life”. The Royal Institution, founded in 1799 to promote the application of science to society, already had a tradition of holding public lectures on scientific subjects, which included live demonstrations of phenomena like chemical reactions, electricity and magnetism. Young accepted to deliver a course of lectures which would cover virtually all of the physical sciences, and on whose preparation he toiled feverishly for the best part of a year. Over 1802–03, he delivered more than a hundred lectures at the Royal Institution; one of his particular ambitions in doing so was to educate interested people who had no access to education, including women. As he later observed in the introduction to the written version of his lectures, “the Royal Institution may in some degree supply the place of a subordinate university, to those whose sex or situation in life has denied them the advantage of an academical education in the national seminaries of learning”. According to contemporary accounts, however, Young’s facility as a writer did not translate into an engaging style of lecturing, and he did not distinguish himself in this role, especially when compared to eminent Royal Institution lecturers like Michael Faraday and Sir Humphry Davy.

Young’s lectures were published in 1807, as an imposing two-volume book titled A Course of Lectures on Natural Philosophy and the Mechanical Arts. In terms of its scope, depth and degree of original insight, this work remains unsurpassed by any other general lecture course written by a single author. Remarkably, the Lectures included not only Young’s lectures from 1802–03, but also a magnificent historical catalogue listing some twenty thousand scientific works in a wide variety of languages, and spanning everything from ancient Greece to his own time. As Robinson rightly states in his biography, “Only Young, among the scientists of his day, would have had the command of foreign languages, combined with the range, judgement and industry to compile such a monumental bibliography”. Ironically, although Young was more than satisfied with the book, his publisher went bankrupt shortly after its publication, leaving him no reward for such a colossal amount of work.

The contents of the Lectures include only too many examples of its author’s tremendous intuition and foresight. First of all, the book contains a description of the experiment for which Young is best remembered today, the double-slit experiment that confirmed the wave theory of light. Here, instead of using the edge of a card (as in his 1803 paper), he cut two narrow slits on a piece of card, which he used to split a beam of light into two beams and observe the fringes of light and darkness produced by their interference. In addition to this, the book includes the first recorded use of the word ‘energy’ in its modern scientific sense (a measure of a system’s capacity to perform work), the first experimental estimate of a molecule’s diameter (whose prescience is underscored by the fact that the existence of atoms and molecules was rejected by most physicists at the time), and an early proposal of the modern notion that different forms of radiation belong to a single spectrum of wavelength, ranging from ultraviolet light on one end, through the colours of visible light, to infrared light (which, moreover, he correctly linked to heat) on the other end. Thus the Lectures, which constitute Young’s greatest written work, evidence that the claim that he was well ahead of his time is no exaggeration.

A selection of figures from Young’s Lectures, including illustrations of the double-slit experiment (top left) and a colour palette (top right) (Young, 1807).

Notwithstanding his trailblazing work in physics and physiology, and the monumental achievement of his Lectures, Young, who was barely thirty years old, was well aware that he still needed to secure a reputation as a practicing physician in order to procure a stable income for him and his wife Eliza, whom he had married in 1804. He tried to attain this by further feats of scholarship: in 1813 and 1815 he published two exhaustive medical volumes, An Introduction to Medical Literature and A Practical and Historical Treatise on Consumptive Diseases. Just as he had done for science, he not only condensed contemporary medical knowledge, but also catalogued the literature of the previous two thousand years. Nevertheless, instead of granting him reputation as a respectable physician, these two books promoted an undesirable image of Young as a ‘cold man of science’, and antagonised his colleagues by offering too clear a view of the abundant flaws and failures of nineteenth-century medicine. The disappointment caused by the reception of his books was probably the main factor which gradually pushed him away from his ambition to become a leading physician, leaving increasing room for his vast array of more absorbing interests.

One such interest was the quest to decipher the writings of ancient Egypt, in which Young would be involved from 1814 onwards. The main driver of the decipherment effort was the legendary Rosetta Stone, discovered by Napoleon’s army in Egypt in 1799. The crucial feature of the Rosetta Stone is that it carries an inscription in three different scripts: Egyptian hieroglyphs, a second Egyptian script known as demotic, and ancient Greek. The Greek inscription was soon translated, revealing that the other two inscriptions contained the same text; this meant that it might be possible to identify equivalent words in Greek and Egyptian, and employ them to crack the hieroglyphic and demotic scripts. Given his vast experience with languages modern and ancient, Young was excellently equipped for this task. By studying the inscriptions in the Rosetta Stone, besides tirelessly copying and comparing hieroglyphic and demotic inscriptions from a myriad of other sources, he was able to notice subtle similarities and patterns which had been overlooked by other scholars. In particular, Young was the first to notice parallels between some hieroglyphic signs and their equivalent demotic characters, and he went on to show that the two scripts were not unrelated, with demotic being actually derived from hieroglyphic. From this insight, he realised that the demotic script comprised “imitations of the hieroglyphics … mixed with letters of the alphabet”; it was, in other words, a mixture of symbolic characters representing concepts, and phonetic characters representing sounds.

In 1819, Young published a historic article titled ‘Egypt’ in the Encyclopaedia Britannica, which contained the first systematic attempt at deciphering ancient Egyptian writings. In over thirty thousand words, the article presented Young’s results since he began studying the scripts in 1814, including a dictionary with proposed translations for more than four hundred hieroglyphic and demotic words, as well as a tentative ‘alphabet’ for the demotic script. These unprecedented advances were made possible by an earlier suggestion that non-Egyptian names in the inscriptions might be spelled phonetically, in both the demotic and hieroglyphic scripts. Young proved that this was the case by translating the hieroglyphic inscriptions for the names of King Ptolemy and Queen Berenice (though not all his phonetic guesses were correct). Most notably, this article was published anonymously, as Young had by then started to conceal his non-medical research to avoid damaging his reputation as a physician. And, despite having been the indisputable leader of the decipherment effort until then, his endeavour to remain anonymous would prove more harmful than beneficial once the French Egyptologist Jean-François Champollion came onto the scene in 1821.

A letter written by Young in 1818, where he advances meanings for certain groups of hieroglyphs (including the names of Ptolemy and Berenice), most of which were correct (The British Museum).

Champollion and Young were bound to become rivals. For a start, they had opposite personalities: Champollion, who is now considered the father of Egyptology, was passionately devoted to the civilisation of ancient Egypt, and had long wished to visit the Mediterranean country and explore its monumental ruins. His temper, moreover, matched his zeal: he was prone to displays of extreme emotions, and harboured a burning desire for the glory of deciphering the hieroglyphs. Young could hardly have been more different: an incorrigible polymath, his interest in the scripts of ancient Egypt never extended beyond the itch to crack a philological puzzle; he had a calm and candid disposition and, according to his friend Gurney, he “could not bear, in the most common conversation, the slightest degree of exaggeration”. Significantly, it was Young’s own self-deprecation and his anonymity as a researcher which enabled Champollion to claim the sole credit for the decipherment of the hieroglyphs, despite the plain fact that his technique was built upon Young’s earlier findings and his tentative Egyptian dictionary. In fact, a former teacher of Champollion, Sylvestre de Sacy, warned Young as early as 1815 that he should be careful in sharing his discoveries with the French scholar, for “he may hereafter make pretension to the priority”.

Just how much Champollion benefitted from Young’s work can be appreciated by examining his major publications. The first of these appeared in 1821, while he was still oblivious of Young’s 1819 article. Two facts about this publication are very notable: first, Champollion put forward the seriously mistaken notion that the demotic script was composed entirely of conceptual symbols (while Young had already shown that it included phonetic symbols as well); second, once he had come across Young’s article in Paris, it seems that Champollion made a herculean effort to withdraw every single copy of his own article, and was careful not to refer to it in his subsequent publications of 1822 and 1824. Most tellingly, he also avoided any mention of Young’s previous identification of the meanings of many hieroglyphs, including his partly correct deciphering of the names of King Ptolemy and Queen Berenice, as well as other crucial findings, such as the use of certain symbols to indicate female names. When making use of these previous discoveries in his research, Champollion simply referred to them as part of his deductive process, thus implying that they were either well-known facts or his own findings. In reality, the insights gathered by other scholars served him as an essential stepping stone that allowed him to finally decipher the entire hieroglyphic script; what is most disturbing is not the fact that he built on these earlier results — which is a natural part of research — but rather that he adamantly refused to concede any recognition to their original authors. An understandably irritated Young was swift to point out that Champollion had attained his goal “not by any means as superseding my system, but as fully confirming and extending it”. Their irksome dispute notwithstanding, Young never failed to laud Champollion’s crucial contributions to the decipherment; he simply wanted his own contributions recognised. With the benefit of hindsight, it is clear that Champollion was doing himself no favour by insisting on claiming all the credit for the decipherment of the hieroglyphs: the breakthroughs that he achieved in 1822–24, his pioneering explorations of Egyptian ruins and monuments, and his publication of the definitive statement of the decipherment, would undoubtedly have sufficed to secure his legacy as the founder of Egyptology. Instead, Champollion’s egotism became an indelible stain on his reputation; brilliant and industrious as he was, he is also remembered as an arrogant and somewhat dishonest scholar.

Despite the manner in which Champollion had overtaken him and seized the hieroglyphic laurels, Young did not cease to work on the writings of ancient Egypt; after all, the demotic script remained undeciphered, and he now seemed to be in a position to crack it. This was largely due to a providentially helpful papyrus which he encountered in 1822, containing a Greek translation of a demotic text that Young had already spent much time trying to decipher. Thus he expressed his exhilaration at the sheer improbability of this event: “a most extraordinary chance had brought into my possession a document which was not very likely, in the first place, ever to have existed, still less to have been preserved uninjured, for my information, through a period of near two thousand years: but that this very extraordinary translation should have been brought safely to Europe, to England, and to me, at the very moment when it was most of all desirable to me to possess it…”. Notably, Champollion himself, possibly more relaxed after having become a prestigious curator at the Louvre Museum in 1826, offered Young the use of his private notes on the demotic script. With these new resources in hand, Young finally completed the decipherment, becoming the first person to read a demotic text in more than a thousand years. From that moment until his death, he continued to work on what would be his final opus, Rudiments of an Egyptian Dictionary in the Ancient Enchorial Character, published posthumously in 1831.

Three pages from Young’s Rudiments of an Egyptian Dictionary, presenting the meanings of groups of demotic characters (Young, 1831).

It would be easy to believe that the study of Egyptian writing systems, combined with his medical obligations, absorbed all of Young’s time after 1814; but nothing could be farther from the truth. In fact, his polymathic tendencies became even more evident during this period. To begin with, between 1816 and 1825 Young contributed a total of 63 articles to the Encyclopaedia Britannica, writing on an astonishing variety of topics including languages, ocean tides, hydraulics, bridges, Egypt, carpentry, road-making, steam engines and integrals. Some of these articles went beyond mere reviews of existing knowledge, presenting some notable original insights. In addition to the pioneering work on the hieroglyphs in his article on Egypt, Young’s article on languages is particularly noteworthy. In its thirty-three thousand words, he applied his philological knowledge to examine and compare some four hundred ancient and modern languages from across the globe, and classified them into families on the basis of their degree of similarity. In this analysis, he coined the now-popular term ‘Indo-European’ for the family of languages comprising most of the Indian, West Asiatic and European tongues. Young, however, made anonymity a condition of his contributions to the Encyclopaedia; he would not agree to attach his name to his writings until 1823, by which time he had abandoned his ambition of becoming a leading physician.

One factor, besides the underwhelming reception of his books, which prompted Young to gradually steer away from his medical aspirations, was the increasing financial security brought by the multiple government-funded positions that he fulfilled from 1811 onwards. The bodies in which he was asked to serve included a Royal Navy committee to evaluate the adoption of an improved method for the construction of ships; a Royal Society committee requested by the government to assess the safety of introducing coal gas in London; a government commission for comparing the French and English unit systems, and considering the adoption of a more consistent system throughout the British Empire; and the government’s Board of Longitude, which was in charge of a scheme of prizes for solutions to the problem of determining longitude at sea. Notably, in 1820 Young used the influence of his position at the Board to convince the government to establish a major astronomical observatory at the Cape of Good Hope in South Africa. It was because of this array of services to his country that he felt confident enough to write, with distinctive wittiness: “But I do not owe the public much, and I suppose I shall never be paid much of what the public owes me”. And even all this does not capture the entirety of Young’s activities during the 1820s: he also published technical papers on such disparate subjects as the shape and density of the Earth and the theory of life insurance; and he was hired as ‘inspector of calculations’ and physician to a newly founded life insurance company — a position so well paid that he asked for his salary to be reduced. More remarkably, Young was also considered as a candidate for the presidency of the Royal Society (which he had served as foreign secretary since 1804), and had he been interested in the position — or “if I were foolish enough to wish for the office” — he would certainly have been elected.

After an adult life of notable good health, in 1828 Young felt an unaccountable fatigue while visiting Geneva. Early in the following year, he started suffering apparent attacks of asthma, and developed progressive difficulty to breathe and weakness. Even when confined to bed, he nonetheless continued to work on the final proofs of his Rudiments of an Egyptian Dictionary, up to the point where he had to resort to a pencil for being too weak to hold a pen. According to George Peacock, a contemporary biographer of Young, when a friend advised the dying man not to fatigue himself with this work, “he replied that it was no fatigue, but a great amusement to him”. He had almost finished correcting the proofs of his book when he passed away on 10 May 1829, just a month short of his fifty-sixth birthday. An autopsy of his body revealed ‘ossification of the aorta’, today known as advanced atherosclerosis: his aorta had become calcified, hard and narrow, which in the end probably caused progressive kidney failure and pulmonary edema. Why Young suffered from such an advanced form of this disease in his middle age remains a mystery.

Young’s death attracted very little public response. Eulogies were read at the Royal Society and the National Institute of France (which in 1827 had elected Young as foreign associate, an extremely prestigious honour), and a terse note reporting his death was published in the medical journal The Lancet. It was only thanks to the campaigning of Young’s widow Eliza, and his lifelong friend Hudson Gurney, that a memorial plaque was eventually installed in London’s Westminster Abbey, granting Young an immortal place among some of the greatest scientists and artists in British history. Eliza Young is also to be thanked for convincing Peacock to tackle the daunting task of writing a biography of her late husband.

With an unparalleled range of serious academic interests and original contributions to science and scholarship, there can be no doubt that Young was the greatest polymath of his time, even by admission of many of his own contemporaries. It is truly difficult even to grasp how much knowledge he acquired over his five decades of life. Had Nobel prizes existed in the nineteenth century, Young would probably have been awarded one in physics for his demonstration of the wave theory of light, and possibly a second one in physiology for his work on human vision. History, however, is notoriously unsympathetic to polymaths, and Young is often summarised simply as a ‘physician and physicist’ — or even just one of the two. His lifelong attitude toward science is perhaps best expressed in a letter to his friend Gurney: “Scientific investigations are a sort of warfare, carried on in the closet or on the couch against all one’s contemporaries and predecessors; I have often gained a signal victory when I have been half asleep, but more frequently found, on being thoroughly awake, that the enemy had still the advantage of me when I thought I had him fast in a corner — and all this, you see, keeps one alive”.

Just as extraordinary as his intellectual motivation is the fact that Young, unlike some of the greatest scientists of the last three centuries, was a sociable and sensitive individual, with a genuine interest in the arts and a distinct fondness of human company. Robinson sums him up as “a lively, occasionally caustic, letter writer, a fair conversationalist, a knowledgeable musician, a respectable dancer, a tolerable versifier, an accomplished horseman and gymnast, and, throughout his life, a participant in the leading society of London”. At the same time, Young was deeply private about his personal life; almost nothing is known about his wife Eliza, for instance, although their marriage is reported to have been a happy one. Eliza was probably a major reason why Young did not become embittered by the many disappointments, offences, disputes and rejections which marked his professional life.

Given the gradual professionalisation and specialisation of every branch of science over the last two hundred years, it is unlikely that we shall see the like of Thomas Young again. His life, however, remains an awe-inspiring testament to the unbounded potential of the human mind, and a prime example of the original meaning of the word ‘philosopher’. For it was his sheer love of knowledge, his unremitting longing to understand the world, which above all defined him, and ‘kept him alive’.

Robinson, A. The Last Man Who Knew Everything. Pi Press/Oneworld Publications, 2006.
Peacock, G. Life of Thomas Young: M.D., F.R.S., &c. John Murray, 1855.
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Young, T. A Course of Lectures on Natural Philosophy and the Mechanical Arts. Joseph Johnson, 1807.
Young, T. Rudiments of an Egyptian Dictionary in the Ancient Enchorial Character. J. and A. Arch, 1831.