Body and Soul in Ancient Philosophy

Heraclitus on measure and the explicit emergence of rationality 89
Notice, too, that what I am attributing to Heraclitus is an idea, not a
complete account, much less an analysis, of rationality. Rationality comprises
much more than we find in Heraclitus, including, for instance,
formal proof, rules of logic, or the best means to achieve a given end.
It also involves procedures, such as reductionism and economy of explanation,
which he uses but which are probably not presupposed by
his explicit interest in measure and proportion. Heraclitus’ conceptualization
of rationality, nevertheless, had a profound influence on Greek
philosophy. 3 It also articulated and helped to propagate the pre-philosophical
notion that order and moderation are essential to the proper
functioning of things, whether human or divine.
In order to make the case for Heraclitus’ seminal contribution to the
idea of rationality, I adopt a three dimensional methodology. Of prime
importance, obviously, are the conceptual connexions Heraclitus invites
us to make between the terms metron, nomos, and so forth, that figure in
his most suggestive statements. However, I shall not start from his own
text because any progress we can make in understanding Heraclitus’ idea
of rationality requires us to situate that idea within his cultural context.
Which brings me to the other two dimensions of my methodology.
When we do the history of philosophy, we generally proceed by
asking how a given thinker positions himself in relation to his predecessors,
following the forward arrow of time. Heraclitus himself, moreover,
requires us to do this because he alludes so pointedly and critically to the
older authorities Homer, Hesiod, Pythagoras, Hecataeus, and Xenophanes.
4 He must suppose that these authorities have failed to grasp
and live up to his idea(l) of rationality, which does not imply, of course,
that he has failed to learn from them or could have thought as he does
without them. Hence a further dimension of my inquiry will involve us
in asking what we can learn about this idea by viewing it against the
background of earlier Greek thought. Important though this background
is, what we can learn from it is severely limited by the huge
gaps in our knowledge. What, for instance, was it about Pythagoras
that irked Heraclitus so much? If Pythagoras had the interests in musical
3 Plato, Aristotle, and Stoics frequently signify the normative sense of rationality
with the expression orthos logos. Translators typically render this phrase by “right
reason” or “correct rule”, but they would do better, in my opinion, to opt for
“correct ratio” or “right proportion”, in line with what I take to be Heraclitus’
seminal conception of rationality.
4 B 17, 40, 42, 57, 67.