The Greeks

Collecting Cuttlefish on Lesbos

The Lagoon: How Aristotle Invented Science
By Armand Marie Leroi (Bloomsbury 512pp £25)

Aristotle and Plato - their names conjure up thoughts of stone busts showing serene elderly men with long curly beards. Perhaps these revered Greek philosophers really did look like that at some stage in their lives, but according to the evolutionary biologist Armand Marie Leroi, Plato was so irascible that he once threw his favourite dog down a well and his student Aristotle was an overdressed dandy who compensated for his small eyes and thin legs by sporting plenty of jewellery and an elaborate hairstyle. Leroi also sets out to challenge traditional impressions of their intellectual activities. He makes little mention of the usual philosophical sound bites - shadows on the walls of a cave or syllogistic puzzles about the mortality of men. Instead, in Leroi's revisionist version of the Academy in Athens, Plato emerges as an anti-scientific mythmaker mindlessly obsessed with numbers, while Aristotle is cast as the world's first scientist and the founding father of biology.

As the title of Leroi's latest book, The Lagoon: How Aristotle Invented Science, suggests, Aristotle is Leroi's scientific hero, the essential precursor of Georges Cuvier, Charles Darwin, Gregor Mendel and all the other great men of the life sciences (virtually the only reference to women occurs when the author exchanges conquest notes with a scientific colleague in a harbour café). Even when admitting that Aristotle got it wrong by modern standards, Leroi finds ingenious reasons to let his hero off the hook. Earlier speculative philosophers, he writes, had condescendingly viewed the world from the mists swirling around Mount Olympus, whereas Aristotle stepped down to investigate the realities of life on the shore.

Leroi clearly adores Greece and he uses his detailed local knowledge to splendid effect, evocatively re-creating the experiences of this peripatetic philosopher, who wandered to the far reaches of the empire and for a while was employed as tutor to the young Alexander the Great. Much of Aristotle's zoological research was carried out on the island of Lesbos; Leroi adopts lavish tourist-brochure prose to depict not only the sun-baked scenery but also the coloured plumage of the birds, the iridescent insides of a cuttlefish and the spiral whorls of a nautilus shell. He regales his readers with the gastronomic delights that can be experienced only by eating fish freshly plucked from the sea (including esoteric parts of sea urchins), cleverly using what might otherwise seem culinary diversions in order to weave together accounts of modern classification, mythological creatures and Aristotle's own approach to species distinctions. While Leroi would like to see Aristotle as a proto-Linnaean, some local fishermen explain to him that, for them, taxonomical categories are never absolute: how they label any individual fish depends not only on its appearance, but also on other factors affecting its taste - where it was caught, its age, its diet.

Aristotle was an exceptionally talented observer; he may have lacked a microscope, but he looked closely, dissected carefully, described clearly and was evidently familiar with non-European fauna. As if a chameleon were laid out in front of us, he makes us see that its body

is rough, like a crocodile's. The eyes, very large and round, are covered in skin like the rest of the body and located in a cavity: in the centre is a small hole through which it sees and which is never covered by skin ... Its change in colour occurs when puffed up, when its colour is actually black, not unlike a crocodile, or green like a lizard with black spots like a leopard ... Even after it has been cut open completely, the chameleon continues to breathe for a long time and a tiny motion remains around the heart.

At times, however, Aristotle relied on facile assumptions or allowed mythical stories to creep in. Despite mastering the complexities of a cuttlefish's abdominal tract (it defecates on its head) and the ambiguities of hyena genitals (don't ask), he miscounted the number of vertebrae in a lion's neck, declared that ostriches have hooves and maintained that asses are well known to wage war on lizards, which prevent them from eating by climbing up their nostrils.

The Lagoon is a book written by a scientist for other scientists - or rather, for anyone who shares Leroi's blithe confidence that only science can yield true and useful knowledge about the world. Like those old films where the goodies and the baddies are distinguished by the colours of their hats, Leroi's world is split into two camps. While Aristotle leads scientists on the route to progress, Plato - along with most other philosophers - is relegated to the side of the losers. Fortunately for Plato, Aristotle read his great dialogue about nature, Timaeus, and 'transmuted its conceptual lead into the gold of scientific explanation'.

As Leroi observes, science is cumulative. The path towards the future is influenced by the roads already travelled - or, as John Maynard Keynes put it, we should think of Isaac Newton not as the first great scientist, but as the last man to view the world through the eyes of his predecessors. Leroi is absolutely right to say that even those sections of Aristotle's work we no longer believe to be correct have affected the knowledge that we have today. Where Leroi goes wrong is to deny that the Bible or any other religious texts have been important for science. The Aristotelianism prevailing in Europe for many centuries was a Christianised version that Aristotle himself might well have rejected. Whatever the intentions of their original authors, accounts in Genesis and elsewhere have had a profound impact on science: it is no coincidence that the big-bang explanation of creation feels intuitively more comprehensible than any Aristotelian-style steady-state theory.

Leroi concludes with Aristotle's famous pronouncement: 'All men, by nature, desire to know.' Interpreting this as a paean to the beauty and value of science, he makes his hero seem prescient by squeezing his concepts into modern formulations. Another way of reconciling the ancients with modernity is to recognise our own limitations and acknowledge that scientists today are no more successful than were the Greeks in answering the truly big questions: How was the universe created? How can life emerge from matter? How are mind and body related?