The Lagoon: How Aristotle Invented Science

by Armand Marie Leroi

Viking, 2014

We typically refer to Aristotle as the first systematic philosopher in the West, (Dante, for instance, often referred to him simply as "The Philosopher") and that forms a neat continuity with his mentor Plato and Plato's mentor Socrates. But we only have a third of the books Aristotle wrote in a long lifetime full of writing, and what we know about what we don't have leads to the central opening assertion of Armand Marie Leroi's uproariously enjoyable new book The Lagoon: How Aristotle Invented Science: "To be sure, some philosophers and physicians had dabbled in biology before him, but Aristotle gave much of his life to it," Leroi writes. "He was the first to do so. He mapped the territory. He invented the science. You could argue that he invented science itself."

Of course, even as a scientist, Aristotle has his critics - including the smartest man in the Renaissance. Francis Bacon takes the ancient master to task for "undertaking not only to frame new words of science at his pleasure, but to confound and extinguish all ancient wisdom, insomuch as he never nameth or mentioneth an ancient author or opinion, but to confute and reprove ..."Leroi instantly rides to the rescue:

That Aristotle is generous with criticism and parsimonious with praise towards his predecessors is undeniable. But so what? It's a scientist's job to disagree. Besides, the remarkable thing is precisely how each of his books begins with a round-up of what his predecessors thought before moving on to his own solutions. Aristotle's treatises have the structure that academics have used ever since. As Bertrand Russell said, Aristotle was the first man to write like a professor.

The Lagoon doesn't unfold gradually and gracefully; it lunges and explodes all over with wit, erudition, and enthusiasm. Leroi goes to the island of Lesbos and its surroundings, walks around, pokes in the same tidal pools that Aristotle himself must have prowled as part of his inspiration for the many science books he wrote when he wasn't yarning on about philosophy. Leroi is a big fan of those books; they set his imagination working:

The books that we have are a naturalist's joy. Many of the creatures that he writes about live in or near the sea. He describes the anatomies of sea urchins, ascidians and snails. He looks at marsh birds and considers their bills, legs and feet. Dolphins fascinate him for they breathe air and suckle their young yet look like fish. He mentions more than a hundred different kinds of fish - and tells of what they look like, what they eat, how they breed, the sounds they make and the patterns of their migrations. His favourite animal was that weirdly intelligent invertebrate, the cuttlefish. The dandy must have plundered fish markets and hung around wharves talking to fishermen.

This is a very entertaining author, one who layers an arch wryness over almost everything he writes about (mentioning the first century AD polymath Pliny the Elder, for instance, he says, "He said that he valued first-hand reports, but didn't mean it"), very much including his contrary hero, whom he lauds very perceptively for his groundbreaking physiological explorations but nevertheless resists the urge to make warm and cuddly:

Aristotle says that tortoises hiss, copulate and have shells. They also have large lungs, small spleens, simple stomachs and a bladder; male tortoises have internal testes and seminal ducts that converge in an 'organ'. So he evidently dissected one. At least one tortoise came under his knife while still alive for he also says that if you cut out a tortoise's heart and then put its shell back on it will keep wriggling its legs. Aristotle doesn't have pets; he has specimens.

Leroi takes his readers through the whole gamut of the natural world as it's addressed by Aristotle, from animals to embryology ("following Aristotle's precepts if you want to father a daughter first take a long, cold shower, try your best and reflect that it beats ligating a testicle") to earth science to cosmology, and before Leroi has gone on very long, he's certainly made his case that we ought to regard Aristotle's science-writing on at least a par with his philosophizing. And we quickly realize that Leroi, a professor of evolutionary biology at Imperial College London, is no slouch himself at writing science for the general reader. Take for instance the elementary question of why old age exists at all. "Aristotle sidesteps the question," Leroi tells us. "He says that it is just the 'nature' of living things on earth to age and die. All that remains to be discussed is how and when. Darwin sidestepped it too. He said even less. The omission was glaring." The current thinking on the subject is then adroitly illuminated:

Modern evolutionary biologists demur. They point out that 'good of the species' arguments are weak and at best a last resort. They argue instead that ageing is the result of the absence of natural selection. Most animals and plants have a constant risk of death from external causes such as accident and disease and since the dead cannot reproduce old age is invisible to natural selection. This invisibility means that bodies are designed to work when young but fall apart when old. When, therefore, we ask what ageing is for we must give the peculiar answer that it isn't for anything; it is, instead, the evolved consequence of there being no reason to stay alive.

Wonderfully, The Lagoon ends with a series of appendices in which Leroi presents "some of Aristotle's data and models as he might were he writing now: in tables and diagrams." This is a fantastic, eye-opening innovation, a perfect capstone for a book that does so much to level the playing field for Aristotle the scientist (even the first scientist). Leroi assumes that the scientists looking at some of his simulations "will only wonder how Aristotle got as far as he did using mere words." To which Leroi supplies, "I would ask them to remember that although he was smart, he did live a long time ago." Anybody reading The Lagoon will come away feeling he didn't live nearly as long ago as they used to think.