The Lagoon: How Aristotle Invented Science

by Armand Marie Leroi

The belief that living things transform food into uniform parts hardly seems like a stunning insight, yet it seems to have been original to him. He says that his predecessors had two views about how the uniform parts grow. Some held that creatures make more of x (flesh, bone, whatever) simply by eating x. Call it the ‘additive’ model of nutrition. Others were more subtle: they held that creatures make more of x by eating its opposite. This ‘anti-matter’ theory is hard to understand and Aristotle’s illustration of it, that ‘water may be said to feed fire’, isn’t very helpful, but it does contain – albeit in peculiar form – the idea of transformation. Aristotle acknowledges, then, that the ‘antimatter’ theory contains a germ of truth. Even so, he’s clear that a much more general theory of transformation is needed. Some chemical notation shows what an advance his theory was over his predecessors’. If the ‘additive’ theory is written x → x, and the ‘anti-matter’ theory is anti-x → x, then Aristotle’s general theory is x → y. Or, to use his words, one kind of matter, x, ‘passes away’ even as another, y, ‘comes to be’. But actually that’s too simple, for Aristotle thinks that uniform parts arise from a system of serial and parallel transformations: x → y → z etc. or x → y + x → z etc. That is, he thinks that metabolic transformations are ordered as a chain or even a network. From this simple, yet pregnant, idea Aristotle constructs an entire system.