What​ are the people in our lives really like – inside? Seeming and being may not be the same. Smiles may be false and vows of love insincere. Appearances are deceptive; you can’t tell a book by its cover; beauty is only skin deep. Yet, in ordinary circumstances, surfaces are all we have to go on. We do often infer something about books from their covers.

Physiognomy was the name the Greeks gave to the art of judging character and mental tendencies from the body’s surfaces and visible behaviours. Aristotle’s Physiognomonica considered all sorts of surfaces and bodily presentations – complexion, hair colour and texture, timbre of voice, gait – but as the art developed over the centuries, through the Renaissance and after, the physiognomical gaze was focused largely on the face, its overall size and shape, and the arrangement of its constituent parts. From the early 19th century, the adherents of the related practice of phrenology felt the bumps and declivities of the skull to gauge the strength of distinct underlying mental faculties – benevolence, combativeness, wit, wonder and so on.

‘An alteration in the state of the soul produces an alteration in the state of the body,’ Aristotle wrote. This general sort of inference from exterior appearances to interior states also belongs to ordinary social interaction, the way we take the body’s surfaces and movements as suggestive, if not definite, signs of states and intentions. Faces, and more specifically eyes, are traditionally said to be ‘the window to the soul’, though not everyone has been convinced the window is transparent. In Macbeth, King Duncan confesses that he has disastrously misread the traitorous Thane of Cawdor: ‘There’s no art to find the mind’s construction in the face.’ But the audience at the Globe knew very well that such an art was widely advertised and practised, even if there was no certainty in it. And in the very next scene, Lady Macbeth counsels her husband on how to arrange his face: ‘Your face, my thane, is as a book, where men/May read strange matters. To beguile the time,/Look like the time. Bear welcome in your eye.’

As a sign of what’s inside, the face has pride of place: it is, after all, hugely expressive. It is where the organs of speech are to be found, and is capable of communicating much while saying nothing. Volitional facial expressions and speech belong, as the sociologist Erving Goffman wrote, to the domain of ‘expressions given’, while poorly delivered compliments or facial expressions not intended to be noticed are ‘expressions given off’ – information about what you’re like and what you think that aren’t in your ‘script’.

But the body has another major organ for conveying meaning and emotion – or, rather, it has two of them. Through the hand and its gestures, we can greet, promise, threaten, console, assent or reject, and much else besides. The hand can direct attention or outline a rough but reliable picture of the world – ‘It’s over there’; ‘It’s that big’; ‘It’s shaped like this’ – while sign languages translate the spoken word into hand movements. The hand is also a major instrument of the will, acting on and in the world: through its muscular motions, the hand grasps, strikes, plucks the strings of a guitar, lifts food to the mouth, and so on. Through touch, it is an instrument for conveying rich information about the world to the brain. There are dense neural connections between hand and brain, and each leaves its mark on the other. Some late Victorian anatomists and physiologists believed that all the brain’s thoughts influenced the hand, and early 20th-century phenomenologists liked to say that ‘the hand is the visible part of the brain.’ It’s an organ through which we know about the world, and in its expressive mode it helps others know something about us. But the hand might also be thought to contain information about the mind; it might, indeed, have information inscribed on it, making it a surface to be read and interpreted.

It isn’t obvious how to read the information a hand has to offer – though some things seem straightforward. Othello tells Desdemona that her ‘hot and moist’ hand ‘argues fruitfulness and liberal heart’; a handshake ‘like a wet fish’ signals disengagement; and the 29-second-long handshake in 2017 between Trump and Macron was a macho war of wills. A delicate pale hand might indicate that someone doesn’t do manual work; the aged were said to be ‘hoary-handed’ (grey and withered), while sons of the soil are ‘horny-handed’ (rough and calloused). But there was also a purportedly expert practice of reading the hand, called chirology (from chiro, ‘hand’, and logos, ‘knowledge’) or chiromancy (divination by the hand).

Decoding the Hand tells a story, extending from the deep past to the near present, about the way the hand has been read, the meanings that have been discerned, the different sorts of people who have interpreted the signs, the links between hand-reading and philosophy, science and medicine, and the stances taken on these matters by law, religion and government. Alison Bashford is an Australian historian whose previous books have included a close study of Malthus’s Essay on the Principle of Population and a remarkable biography of the Huxley family, but here she has produced something altogether surprising and hard to categorise – a story which is, on the one hand, just about a bit of the human body and, on the other, about the changing, contested and consequential practices through which we have sought to know ourselves and others.

The Greeks had no monopoly on hand-reading. It was described in the Kabbalah, in ancient Sanskrit texts, and in writings from Persia, China and Arab cultures. Most consequentially for European history, in the 19th century hand-reading was associated with ancient Egypt – from where it was believed to have diffused to Greece and Asia – and with the Gypsies, so called for their supposed Egyptian origins.* That is, the exoticism of reading signs on the hand was linked to distant times and cultures – which made it an object of both fascination and repulsion.

Chirology was the fancy term for hand-reading while palmistry was the more demotic form, and the two designations largely coexisted until 19th-century product differentiation painted palmistry as unsatisfactorily crude and folkish. For both, the surfaces to be interpreted included the now well-known lines on the palm – the heart, head, life and fate lines (their length, depth, continuities and discontinuities), and their many tributaries – but practically every other visible feature of the hand too: overall shape, colour, texture, length of fingers and their mathematical relations to one another, the appearance of the nails, ‘mounts’ (or raised bits below the fingers), papillary ridges on the fingertips and so on. Hand patterns were hugely complex, and if you wanted your hand read, you needed to consult an expert. Even that might not resolve matters since there was much disagreement over which signs were significant and how to read them. Did you read the right or the left hand, and were there informational differences between them? What about men versus women? Which palmar marks testified to the lived past and which to the future?

‘Nothing is so secret in a human being that it does not have an outward sign,’ the Renaissance natural magician Paracelsus pronounced. The ‘doctrine of signatures’ held that the visible surfaces of plants revealed interior natures, essences and powers. The same applied to what was inscribed on the human hand. In traditional palmistry, the marks might be understood as God’s handiwork, indicating what people were like, or, formally distinct from theological frames, the hand’s surfaces might testify to celestial influences. Hence the mounts of Venus, Jupiter, Saturn and the Moon, the physical characteristics of each signifying aspects of human nature – sensuality, authority, steadfastness and the like – just as, in astrology, people born under the sign of Virgo tended to be detail-orientated. Palmar lines also had a geometry, and Kabbalistic palmists devised elaborate numerological schemes to decode lines, proportions and geometric relations. So the hand could be read because your body was marked with cosmic meaning in a not yet disenchanted world.

Reading the hand was a way of telling you what you were like and what the future held for you. Future-telling was as attractive in the marketplace as it was problematic in theology and law. Renaissance and early modern religious authorities took a dim view of claims to know what properly belonged only to God. Drawing on Old Testament authority, the Catholic Church banned ‘all forms of divination’, explicitly mentioning ‘palm-reading’, and in some strands of Protestantism your fate was sealed when you came into the world but the only ways you could know that fate were through the inner glow of faith, the embrace of righteousness, or the doing of ‘good works’ – taken as an outward sign of an inner state of grace. There were also worries about the circumstances through which your fate might be known, if such a thing were possible – divination might involve the devil.

In 16th-century English legislation, those who practised palmistry, physiognomy and other modes of fortune-telling were put under penalty, imprisoned or required to leave the country. These fortune-tellers were foreigners – ‘certayne Persons calling themselves Egyptians’ had come into the country – and hand-reading was branded an alien import. The law, however, did not then see palmistry as diabolical. The Witchcraft Act of 1735 made it illegal to tell fortunes, but palmists weren’t considered to be witches – there were no such beings. Instead, they were frauds. Fortune-telling was later subsumed under the Vagrancy Acts; the reasoning, again, was as much about fortune-tellers being a certain sort of foreigner as it was about their taking money through deceit. Section 4 of the Vagrancy Act of 1824 classified as ‘rogues and vagabonds’ anyone using ‘subtle craft, means, or device, by palmistry or otherwise’ to deceive the people. Renaissance and early modern scholars produced erudite chirological texts, convinced that, given sufficient bookish expertise, the meaning of palmar lines and mounts could be powerfully decoded. But hands were read by the non-learned too: the Roma – or those tricking themselves out with what was taken as Gypsy gear – continued to ply their trade through the 19th and 20th centuries, as some still do. The criminalisation of fortune-telling and the historical shift from witchcraft to vagrancy were about many things, but the Roma were among them. Prohibition was an effort to ‘take back control’. An enduring feature of hand-reading was the cultural and legal contest over the right to do it, and over what one could discover when it was properly done.

In Edwardian Blackpool, Roma pitched their tents on the beaches, serving the fortune-telling needs of the holidaying working classes, while the entrepreneurial (non-Roma) Ellis family set up in respectable brick and mortar premises, publishing a monthly magazine titled Know Thyself and offering the middle classes health advice that included physiognomy and phrenological skull-reading as well as palmistry. Chirologists with scholarly and professional credentials (including fellowship in the Royal Society) serviced the fashionable, reading the hands of politicians, artists and intellectuals – their many devotees included William Gladstone, Joseph and Austen Chamberlain, Virginia Woolf, George Bernard Shaw and Oscar Wilde. (A hand-reader pronounced Wilde’s head line ‘very strongly marked, showing extraordinary brain power and profound scholarship’.) The high-end chirologists advertised distinctions between what they offered clients and the vulgar palmistry that was practised on the piers and the beaches. The Roma were ‘charlatans, thieves, rogues or vagabonds who have unfortunately trespassed in all ages upon the fair domains of Cheirosophy’, and the professionals eagerly looked forward to ‘the extinction of the Gypsy fortune-teller’. Polite chirology, they held, was no merely mechanical art: real skill was needed holistically to assess ‘the form of the hand, its consistency, and … the relative sizes of its different parts’. Not any old fool could do it; you needed proper training and long experience. The chirologist was to be transformed from seer to scientist.

Different sorts​ of hand-reader delivered different interpretative goods. There continued to be a market for palmistry as fortune-telling in the 19th and 20th centuries, but upmarket versions tended to veer away from telling you what would happen in favour of telling you who you were. Prudence encouraged probability: your hand testified to what might befall you, not what certainly would. If you had a life line showing serious illness on the way, you were encouraged to adopt healthy habits and so avoid disaster: forewarned was forearmed. Hand-readers told fortunes in just the same way as the physicians did, inferring bodily futures from present signs. ‘We can diagnose a case just like a doctor,’ according to a text from the 1920s titled Medical Palmistry, ‘and tell a client things which may happen under certain conditions.’

In the chirological tradition, astrally or divinely marked hands were signs of internal states, but in the 19th century there were practitioners who deployed a secular causal idiom. The shape and markings of the hand must have something to do with parental legacies, but so too did a person’s way of life, which tracked back to their inner mental and emotional make-up. ‘As certain habits and characteristics produce certain developments of bone and muscle,’ one Victorian chirologist wrote, ‘so from the appearance of those developments in a hand may the habits and characteristics of a subject be unmistakably inferred.’ The hand then appeared as an ‘index of character’, and a natural history of the hand might take the place of natal influences from the gods and the stars. George Orwell wrote that at fifty ‘everyone has the face he deserves’ – that is, physically formed through an interplay of experience and innate endowment – and the same sort of thing could be said about the hand. Into the 20th century, physicians and scientists worked to find out when the main palmar lines were laid down and which natural processes caused them (in the foetus, by about twelve weeks, through flexion), whether they changed during a lifetime (a bit) and (as it turned out, crucially) whether the pattern of an individual’s hand was unique.

In traditional medicine, what you were like could be described through ‘temperament’, ‘complexion’ or ‘constitution’. This language – inherited from ancient dietetic medicine – was still current in the Victorian and Edwardian periods, but ‘character’ and ‘personality’ were increasingly preferred. Chirology emerged as a mode of psychological analysis and, by extension, of therapy. Bashford writes that the vocabulary of chirology, in its linking of surface appearances to deep psychic structures, ‘anticipated’ later categories of ‘psychological archetypes and psychoanalytic interiors’. ‘Nothing is hidden’ from the skilled hand-reader, Katharine St Hill, a therapeutically inclined hand-reader, declared in the 1920s. ‘The human soul is unmasked to your eyes, its motives, principles and strings of action revealed.’ And in the 1940s the physician Charlotte Wolff, a London-based German exile from the Nazis, glossed palmar lines with Freudian vocabulary: one pattern was a sign of ‘conflict between the ego and the id’; ‘the left is the hand of the subconscious mind and the primary emotions.’ Hand-reading was, Bashford says, ‘part of the history of a modern search for a self’, its language changing with historical changes in conceptions of the self’s structure and dynamics.

In the 19th and 20th centuries, while hand-reading might tell what you were really like as an individual, Darwin’s work supplied a new vocabulary for describing what whole groups of people were like. For those in the West looking for ways to grade the races on an evolutionary scale, the human hand was an attractive sort of evidence. The varieties of humankind were also matter for medicine, and particularly for those branches of medicine that dealt with the mental and the moral. In the 1860s, John Langdon Down, medical superintendent of the Earlswood Asylum for Idiots in Surrey, noted that the faces of certain patients had the characteristics of different ethnic groups; he named one syndrome ‘Mongolism’ and the afflicted as ‘Mongoloids’.

Down’s successors turned their attention to these patients’ hands. The roughly parallel palmar heart and head lines – clearly distinct in ‘normals’ – joined together in one continuous transversal line in ‘congenital idiots’. In the 1870s, a French anthropologist observed similarities between this kind of human hand and the hands of apes – hence the designation of the ‘simian line’ as a then-accepted mark of Down’s syndrome and other mental disorders. Later, the physician Francis Crookshank maintained that Down’s syndrome babies were atavistic evolutionary leftovers. Not all of those with hands so marked were ‘idiots’ or ‘imbeciles’: instead, he insisted, they might ‘pass’ as normal (the title of his notorious study from 1924 was The Mongol in Our Midst), so tapping into a panic about British racial degeneration that had been growing for decades. Physicians’ interest in the shape of hands and their marks persisted into the mid-20th century. Neurologists are now sceptical that the single transverse palmar crease is a reliable diagnostic sign: it is said to appear in only about half of Down’s syndrome people and is associated with foetal alcohol syndrome and other chromosomal irregularities, but it crops up in between 1.5 and 3 per cent of the population, many of whom have no abnormal conditions or health problems at all.

In the 1880s, the parts of the human hand that most intrigued the statistician and eugenicist Francis Galton were not palmar lines but fingerprints, their patterns endlessly complex and seemingly packed with information – if only the code could be cracked. Galton hoped to find the marks of character, talent, class or race in fingerprint patterns, but failed. What he did find, and what his successors fleshed out, were the reliable marks of individuality. If you could determine that a pattern was specific to a particular person and that it didn’t significantly change over time, then fingerprints could be used in all sorts of practices that involved the firm fixing of individual identity – a bodily signature taking the place of, and more reliable than, one’s signature on a legal document. By the 1890s, fingerprints (and palm prints) had entered forensics – under the name dactylography, to distinguish it from disreputable palmistry – and became a notable feature of policing and the criminal justice system. In Arthur Conan Doyle’s ‘The Adventure of the Norwood Builder’ (1903), Sherlock Holmes not only uses thumbprint evidence to solve a crime but shows Inspector Lestrade that he knows more about fingerprints than the police. Today you don’t have to be a criminal suspect or an immigrant to have your fingerprints read and your identity established: optical and ultrasonic scanners regulate access to all sorts of institutions and make sure your phone responds only to its rightful owner. Fingerprinting isn’t about knowing yourself: it is about the state, and other corporate bodies, having the means to know you – not your interiority, but your unique identity.

‘Know thyself,’ the Delphic Oracle instructed those who consulted it; Polonius told Laertes to be true to himself; and Alexander Pope said that self-knowledge was ‘the proper study of mankind’. It’s a common counsel, but there is a tension in it. Knowing yourself is supposed to be substantially within your own competence, but the injunction to do it comes from an authoritative source, who may then signal when it seems you have achieved it: in the great work of self-knowledge there have always been helping hands. Robert Burns reckoned that other people can know something about us that we do not or cannot know: ‘O wad some Power the giftie gie us/To see oursels as ithers see us!’ Some of that external expertise involves reading the surfaces we present to the world. Palmistry and physiognomy were two enduring modes of reading bodily exteriors to discern internal states.

By the middle of the 20th century, geneticists could look inside our cells and see that Down’s syndrome is a condition caused by the presence of three copies (instead of the usual two) of chromosome 21. They had got behind surface appearances – faces, palmar lines – to genetic realities: genotype not phenotype. You can now spit in a vial, send it off to a commercial lab and, within days, get a report that tells you who you really are – provided you accept that you are your genes. And, if you like, you can have your fortune told at the same time – the likelihood that breast cancer, late onset Alzheimer’s or Parkinson’s disease lie in your future – and what you might do to reduce the risk. Then there are the technologies such as fMRI that look inside our brains and produce images that tell us not so much what we’re like but what we like, what designs, products or advertisements float our boats – again, provided we accept that our experience of liking and disliking is accurately indexed by the ‘lighting up’ of distinct areas of the brain.

Where is palmistry in all this? In 1917 Max Weber declared the modern world ‘disenchanted’. Natural scientific progress spelled the end of supernatural forces and of the magical beliefs that invoked them. For we moderns, whatever is believed about the hand can have no connection to the divine or the astral, and any link between the hand, personality and personal futures has to be described in terms of wholly natural processes. So palmistry belongs to the discredited past just in the sense that it isn’t done in the departments of research universities. But hand-reading is still very much with us. You can make an appointment today for a reading at Selfridges on Oxford Street, and there are about a dozen palmists within walking distance of my home in Cambridge, Massachusetts. Unlike the chirologists of the Victorian period, none of my local practitioners represent what they’re offering as science-like: apart from hand-reading, most of them offer a suite of psychic services, including tarot card and crystal reading, aura analysis, candle meditation, energy balancing and spiritual cleansing.

Satisfied customers post reviews online. Some pay for future-telling, but what people now mostly seem to want is insight – discoveries that may count as revelatory but are held to the standard of pre-existing self-knowledge. Clients of a palmist in Harvard Square applaud her for telling them what they’re really like, deep inside: she ‘told me things about myself that were so realistic that there is no way it could be a statement for anyone else’: she is ‘a gem, she is very insightful and very accurate’. As I finished writing this piece, I thought I really ought to book a reading and get a personal sense of what’s what. The entry-level fee was only $40, but my nerve failed me, and anyway I was unsure I could control my facial expression well enough to appear sincere and open-minded. But then I discovered I could get a free reading online, done by AI. I uploaded a photo of my dominant hand and, within seconds, ChatGPT told me what I’m really like. My hand is of the Earth type, indicating a ‘practical, grounded personality and a strong work ethic’ (yes). I am ‘reliable’ and have a ‘balanced emotional nature’ (exactly). I am ‘loyal in relationships’ (of course!); I have ‘mental endurance’ (that’s right, how insightful); I ‘prefer working with tangible results v. abstract ideas’ (it’s true: I do occasionally write in favour of pragmatism). I’m impressed – by the technology at least.

Bashford describes Decoding the Hand as ‘a continuous history from chiromancy to genetics’ – from Renaissance palmistry to 20th-century dactylography. She isn’t interested in recuperating the reputation of palmistry, but does note the retention of traditional terminology – the mount of Venus, for example, or heart and head lines – in modern expert practices. ‘The hand and its meaning,’ Bashford writes, ‘are always and everywhere.’ Even so, over time, different physical aspects of the hand have attracted attention, different accounts of the origins of its shapes and marks have been given, and radically different interpretations of their meanings have been proposed. Lineage-tracing is one way of telling the story; pastiche is another – the same pastiche of supposedly past and supposedly present that almost delivered me to the local palmist and that made it possible for AI to tell me what I am really like. ‘It is only shallow people who do not judge by appearances,’ Wilde wrote in The Picture of Dorian Gray. ‘The true mystery of the world is the visible, not the invisible.’