To: John B.
From: Geoffrey Klempner
Subject: Thales, Anaximander, Anaximenes on the primary substance
Date: 10 December 2003 15:14

Dear John,

Thank you for your e-mail of 2 December, with your first essay for the Ancient Philosophy program, on the theories of Thales, Anaximander and Anaximenes regarding the primary substance.

Unusually, I am home today, rather than in my office, writing this on my tiny Psion computer. It's a welcome break from routine.

I liked your essay. I am also pleased to see that you have made a very careful reading of the first three units.

Like many students of the Presocratics, you show a strong leaning towards Anaximander. Though many are over-awed by his concept of the Apeiron - which seems far more exciting than the mundane stuffs of water or air, you make the point that this theory 'holds more weight logically' than the alternatives.

At the beginning of your essay, you express your admiration for the 'purity of their thought...they theorized without the chains of modern science to hold them back'. However, it is in fact empirical grounds that you appeal to in criticizing the theories of Thales and Anaximenes.

Although our interest is in the philosophical worth of these theories - the extent to which they conform to reason and logic - I agree with you that it is impossible to ignore the question whether these theories are consistent with our everyday experience. However, we must take care when considering these ideas to rid ourselves of assumptions based on what we know, from our relatively privileged viewpoint, appealing only to what was, or ought to have been incontrovertible fact that anyone could observe.

For example, is it an incontrovertible fact of experience that things in general do not freeze and boil in the way that water does? In one sense, yes. When we heat the pan of water, the water boils but the pan does not melt. However, this was an occurrence which we must assume was as familiar to Thales as it is to us. So he must have conceived of some *explanation* of why this is so.

No doubt, any explanation which succeeds in defending the water theory will be inconsistent with what we now know from science. But as we are only concerned with the logic of Thales' theory, we have to discard that knowledge.

What would Thales have said? I imagine that he would have pointed to familiar observations from such everyday things as cooking. If you replace water in the pan with a few eggs, heating causes the eggs to solidify. That shows that the underlying processes are more complex than we thought. In one of its forms, 'water' boils when you heat it, in another of its forms it solidifies. Theory saved.

Of course, from a scientific point of view this defence is much too easy. There is very little empirical content in a theory which can always say in its defence, 'The result of the experiment was different from what we predicted, but that just shows that we don't understand the underlying processes.' But then, as we have been insisting, that would be far too narrow a way to assess Thales' brilliant conjecture.

A similar point applies to Anaximenes, although Anaximenes does give an account of the 'underlying process'. Why do things 'condense' and 'rarefy' so inconsistently? Anaximenes could say that is merely a reflection of our lack of knowledge of the full picture.

It is worth noting one important difference between Thales and Anaximenes: there is only tenuous evidence that Thales held that everything 'really is' water, as you assume. A more modest interpretation would be that everything merely 'originates from' water. This is relevant to your essay, because it implies that the three theories are not necessarily competing on the same ground. In other words, on the textual evidence it is not clear that all three philosophers were giving a theory of the form, 'Everything that exists is made of X.'

We readily understand the three theories in this simple way because of what we know. On the scientific view Anaximander's Apeiron would be 'energy'. somehow, that doesn't seem very plausible, does it?

Our three philosophers were looking for the ultimate reason why there is order rather than chaos, and all three found that reason in an intelligent or mind-like principle embodied in the primary stuff. This is another reason to be careful in comparing their theories with what we understand by 'science'.

All the best,

Geoffrey