Diving for Aristotle

I’m reading Rebecca Stott’s highly enjoyable book Darwin’s Ghosts, a lively and accessible review of the philosophers, scientists, pundits, and artists who preceded Darwin in the contemplation of evolution. Each chapter discusses a particular group or individual, so I’m getting to know a lot of historical figures in finer detail than I ever have.

Take Aristotle for instance. What do you know about him? Probably more than me. I knew he was a philosopher, but I could never remember if Plato was Aristotle’s teacher or student (ahem, Plato was the teacher). Also I mistakenly thought he was a Greek. Nope. He was from Macedonia, and in 344 BC, that meant he was often treated like an interloper, a metic – an immigrant. He spent a lot of time island-hopping around Greece, teaching, studying, and observing the natural world. He wanted to understand and explain everything, and did not accept myths and supernatural stories in place of the natural laws he sought. He didn’t support the theory of species transmutation over time (Darwin mistakenly thought he did), but he was an intellectual badass who engaged in hands-on scientific study whenever he could.

As is probably the case with most people, it’s the unexpected anecdotes that stay with me when I read biographies. I learned about sponge diving this time. Aristotle was way into sponges – the soft ones that were historically used for everything from bathing to water filters to contraception. Sponges baffled and delighted Aristotle. He couldn’t decide whether to put them into the Animal or Plant category. So he started hanging out with the sponge divers of Lesbos (and yeah I know that sounds like the punchline to a bad joke).

Sponge diving is an ancient form of underwater diving, a rare combination of grace and brutal fortitude that’s both sport and commercial skill. Because Aristotle couldn’t dive (most of the men who did were deaf or deformed from years of enduring the underwater pressure), he had to investigate by asking questions. He interrogated the divers about everything involved in gathering sponges from the sea floor, and about the sponges themselves. Turns out Spongia officinalis belongs to the kingdom Animalia.

There’s a recent New Yorker article about sponges by the wonderful Ed Yong (if you haven’t subscribed to his weekly The Ed’s Up emails, you are missing out). Go check it out.

And that’s all for now – I’ve gotta go hang out with Darwin’s Ghosts.

“Busto di Aristotele conservato a Palazzo Altaemps, Roma. Foto di Giovanni Dall’Orto” by Giovanni Dall’Orto March 2005. Licensed under Attribution via Wikimedia Commons

“Spongia officinalis 001” by H. Zell – Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons