An old dispute among students was ignited when they learned that the body of a crampfish is furnished with a pair of batteries (see last post).

“So: Signor Volta didn’t invent batteries: he discovered them.”

“I know what’s coming. You’re trying to undermine my atheist beliefs.”

“Atheist unbeliefs, you mean.”

“No, he’s right,” said a third speaker.  “They are beliefs. You have to be a believer to think this fish got its batteries by accident.”

This third speaker had expressed such a motif before. He had been struck by the idea that his family’s marmalade cat had a visual mechanism well beyond the understanding of the most brilliant scientist, let alone a cat. And then he had been marvelling at an acorn that he put on his desk: how had this been dropped to earth with the purpose of making itself into an oak tree, where did it get the will to become one, and how did it have the knowledge to do so?

He had arrived at a topos that occupied the Presocratics. Why in the physical world do some things have life, and others not? What is life? And this subject has occupied microbiologists especially in recent decades, once the discoveries about DNA opened the door to the complexities of how the cells of living things have been programmed and microengineered to ensure their reproduction.

By chance this connected with The Frogs, which they were currently reading. Now of all the pleasantries about Euripides which we find in that play, the modern reader can understand only a fraction. But when, before the contest with Aeschylus, Euripides asks to pray to gods of his own, the first one he addresses is αἰθήρ—Ether.  Now this was apparently a key word in the theory of the philosopher Anaxagoras, the friend and mentor of both Euripides and Pericles. His thesis was that the element pervading all living things is νοῦς—Mind, which is nourished by Ether.

Anaxagoras was among the last of the Presocratics. Their theories and speculations about the nature of the physical world came to a halt with the advent of the sophists and of Socrates and Plato, who rejected this kind of study in favour of investigating human behaviour and the nature of the human being. Study of the cosmos and the natural world was put on hold until the arrival of Aristotle sixty years later.