The first experiment?

A view of Etna from Taormina. Photo (cc) Richard Carter.

It’s common to see the roots of science in the world of the ancient Greeks, but is that the same as saying the ancients had a concept of science? I’ve tended to be sceptical of claims of ancient science as it is often accompanied by modern assumptions of what science should be. To some extent there are elements of science in the ancient world, like the drive towards general explanations. But these explanations were accepted or reject purely by force of argument. What is lacking in Greek science, I’ve thought, is experiment. Reason was considered supreme and observation fallible because the senses could be foold.

In the fifth century BC Empedocles argued that everything in the cosmos was made up of four elements: earth, water, air and fire. This was not accepted by some people who couldn’t see how air could be an element. They wafted their hands in front of them to demonstrate that there wasn’t anything there. Empedocles, it is said, showed this was not true by conducting what some people call the first experiment. It is said he took a clepsydra, a jar with a spout. He put his thumb over the spout and pushed it upside-down into a barrel of water. When the clepsydra was submerged he removed his thumb and the air bubbled out, proving it must be a physical substance. It certainly sounds like an experiment, but was it?

An experiment should have more than one result, to allow you to distinguish between two explanations. In this case if the bubbles hadn’t appeared then it would have proven Empedocles wrong. I’m not convinced. If bubbles didn’t come out of the spout would Empedocles really have agreed he was wrong? It’s likely that he would not. It turns out there’s no evidence the experiment occurred. Empedocles described the clepsydra, but he described a girl playing with it. Powell has described it as the simile of the clepsydra. If the clepsydra hadn’t behaved that way then it’s possible that Empedocles would have chosen a different simile rather than say his idea failed. He was thinking about it as a description of what happened rather than as a test.

Another Empedocles moment could possibly be an experiment. At the end (?) of his life he decided to prove he was immortal. He jumped into Mount Etna. If he was mortal he would die, if he was immortal he would live. He body was never found. Only one sandal was found, so the result remains uncertain. Spoiling this story slightly is a comment by Diogenes Laertius who describes it more as a scam than an experiment. He thought Empedocles ran off somewhere to live out his days. I have however recently found evidence of what probably is a description of an experiment and again there’s an Empedocles connection.

The book On Birthdays by Censorinus has recently been translated into English for the first time. In it he describes a debate between several philosophers on the nature of human seed. Empedocles thought that males came from seed flowing from the right side of the body and females from the seed generated on the left side. A lot of the debate in the book is assertions with no evidence but in chapter 5.2 there’s a interesting claim.

Hippon of Metapontum (or from Samos, according to Aristoxenus) believed that seed flows from the bone marrow and thought that his theory was proved by the fact that, if one butchers the males after the animals have mated, no marrow is found, because it has been exhausted, as you might expect.

This sounds like an observation and theory derived from it which could be tested. This is emphasised by the next line.

However, many refute this opinion, such as Anaxagoras, Democritus and Alcmaeon of Croton. They responded that after the mating of the herds, the males had lost not only marrow but also fat and a great deal of flesh.

That does show that people have tested the idea with observations of their own. It does make ancient science more puzzling than before. If the ancients did have a concept of experiment then why didn’t a modern form of science develop?

There are probably several reasons. One difference between modern science is perhaps not so much its components but the integration of various components into one coherent tool. The ancients saw a polarity between reason and experience and thought the two were incompatible. Modern science in contrast works to combine the two. Of course if you want to make a serious attempt to mark the differences between ancient and modern science then it helps if you have a neat and tidy definition of science, but that’s another argument.

Translations by Holt N. Parker in his his translation of the Birthday Book by Censorinus.