To: Tony S.
From: Geoffrey Klempner
Subject: Anaximander versus Anaximenes
Date: 7 October 2002 12:59

Dear Tony,

Thank you for your e-mail of 30 September, with your first essay for the Ancient Philosophy program, in response to the question, 'In the light of the controversy concerning the relative strengths of the theories of Anaximander and Anaximenes, how do you assess the achievements of these two philosophers?'

This has proved quite a popular question. Most of the answers I have seen, however, tend to sit on the fence. 'Anaximander can be praised for this, but Anaximenes can be praised for that'. So it is refreshing to see the case argued strongly in favour of one philosopher over the other -- in this case, Anaximander over Anaximenes.

As it happens, one of the first philosophy books I ever looked at was Popper's 'Conjectures and Refutations'. I remember being greatly impressed by his 'Back to the Presocratics' essay. However, I see now, as I didn't see then, that there are some problems with the argument that Popper puts forward.

The main difficulty, for me, is that of anachronism. The process of 'conjecture and refutation' requires that we have adequate means for refuting a hypothesis. Today, this is the function of experimental testing. However, apart from such quaint examples feeling the temperate of air blown out through one's mouth, or the behaviour of lids on boiling kettles, nothing the Presocratics did or conceived could be described as 'performing a decisive experiment'.

It is not difficult to conjecture that what actually took place when two theories were compared was *argument*. The views were assessed in terms of which reasoning seemed most plausible. (As an excellent illustration of this see Graham Nicholson's contribution, a dialogue based on the Milesians, to Six of the Best on the Pathways site.)

So the criticism can be fairly put that Popper is looking for support for his own 'falsifiability' theory, rather than really trying to understand the Presocratic philosophers, in their historical context. On the other side, it is very inspiring for philosophy of science students to look at the spectacular advances which these early theorists made -- for example, anticipating atomism, or the theory of evolution -- and the enthusiasm with which they put forward their bold speculations.

Where Popper also scores is in pointing out that the theories of the Presocratics were not arrived at through induction. No process of observing cases and generalizing from them would suffice to account for the daring hypothesis of an 'Apeiron', or the theory that rocks, water and fire are *really* different forms of air.

Popper aside, we can reasonably ask how good was Anaximenes' idea that the primary substance changes through a single process of condensation/ rarefaction. Admittedly, this goes back to Thales less spectacular idea that the primary stuff is a common material which we find in the world rather than outside it. However, one can imagine that Anaximenes might have defended his view, not on the grounds that it sits more comfortably with common sense beliefs, but rather as a possible explanation that Anaximander *overlooked*. Apart from Aristotle's objection to Thales theory which you mention -- that if water is infinite then why aren't all other substances absorbed -- there is a much more obvious objection that each substance that we observe in the world has limits to the forms which it can take, dictated by its nature. Water is the kind of thing that turns into ice or steam. It is not the kind of thing that turns into fire. Of course, if we are disregarding common experience, one can simply assert that it *does* change nonetheless, but that leaves an embarrassing gap in the theory. Here Anaximenes comes to the rescue with a coherent explanation that shows how the single substance theory might, after all, be consistent with what we are able to observe of the world around us.

Again, if we are talking of 'myth busting' then a supporter of Anaximenes could argue that positing an unknowable 'Aperion' as the ultimate stuff comes uncomfortably close to positing a magical principle that is not required to conform to the laws which govern phenomena. Indeed, in a Popperian spirit it might be argued that of the two theories, Anaximenes' theory is more *refutable* than Anaximander's because it makes recognizably empirical claims. (As you show with your criticism of the blowing air through one's lips experiment.) By the standards of Popperian 'science', therefore, the Aperion theory is less, rather than more scientific!

I am simply trying to show the possibilities that there are here. As a matter of fact, my own preference is very much for Anaximander over Anaximenes. But this is not because Anaximander was the better physicist, but rather because he sees the possibility that physics might not be the final word, that there are ultimate questions we can ask about existence *as such* which science, concerned as it is with putting forward hypotheses to explain phenomena, is not equipped to answer.

I enjoyed reading your essay, well done.

All the best,

Geoffrey