The Lagoon: How Aristotle Invented Science

by Armand Marie Leroi

Thus the Platonic–Aristotelian vision of nature as a ladder of perfection and its influence. Yet there is another vision of nature’s order that can also be found in Aristotle. Throughout much of his biology he does not speak of a Ladder of Nature, but only of his great, natural groups of creatures, all of which do much the same kinds of things – eat, sense, move, reproduce – but do them in very different ways using very different devices. Just as both these visions appear at different places in Aristotle’s texts, both also appear in post-seventeenth-century zoology. Sometimes they even coexist, albeit uneasily. Even as the Ladder of Nature triumphed, naturalists such as Pallas were protesting that animals, in all their diversity, could not, should not, be forced into a linear scale. In 1812 Cuvier divided the animals into four great groups that he called embranchements: Vertebrata, Articulata, Mollusca, Radiata. ‘It formed no part of my design to arrange the animated tribes according to perceived superiority,’ he wrote, ‘nor do I conceive such a plan to be practical.’ He elaborated his scheme in Le règne animal, 1817. Bold, clear, detailed and synoptic, it made Cuvier famous. It is here that he celebrated Aristotle as his great precursor who, he said, had left hardly anything for his successors to do. Cuvier’s classification, however, doesn’t look very Aristotelian at all. The great division between the bloodless and blooded animals (reformulated by Lamarck as animaux sans...