Joanne asked:

I am doing a paper in school and the focus is on metaphysical and epistemological issues inherent in
the problem of change as it was formulated by Ancient Greek natural philosophical schools. I also
need to relate this to a modern scientific explanation of change. Any help would be appreciated.

============

This is too big an issue to attempt a comprehensive answer here. What I shall do is focus on one
question that is of particular relevance to contemporary physics, the stand-off between the atomist
theory of the Presocratic philosophers Leucippus and Democritus and Aristotle's theory of matter and
form.

What happens when water freezes? The atomists proposed a theory brilliant in its simplicity, which in
its essentials is still accepted today. Water, and ice each have a microscopic structure. The change
from water to ice, or from ice to water does not involve any change in the elements of which the
structure is composed, the 'atoms' of water, or what we now identify as molecules of H20. Rather,
what changes is the structure, the arrangement of the atoms.

Relying purely on philosophical argument for the atomic hypothesis, without any empirical basis for
their claims, the atomists drew the pessimistic conclusion that we can know nothing at all about the
realworld, the world of atoms moving in the void. Such knowledge as we have of our world is based
on sense perception. Yet the qualities that appear to sense perception, according to the atomic
hypothesis, are illusory. In reality, nothing is hot or cold, wet or dry, there are no colours, tastes,
sounds or smells.

Aristotle could not be persuaded to give up the fundamental epistemological principle that human
perception and reason are adequatefor knowledge of the real world. Explanations that posit
imperceptible microstructures are nothing more than unverifiable guesses. We have no way of telling
whether or not they are true. Moreover, he saw an alternative way of explaining change that remained
fully within the bounds of human knowledge.

Before I tell you what the Aristotle's theory is, I will just say that to appreciate the theory, one has to
suppress one's natural reaction — informed largely by our knowledge of contemporary science —
that the explanations it offers are empty and trivial.

Here is the theory, applied to the case of water. Water is a substance, a natural kind, which
possesses a characteristic form.The unique form of water determines its perceptible properties, its
powersand potentialities.Water freezes, because freezing is one of the things that water has the
potential to do. When your finger touches the ice, your finger gets cold because making things cold is
what ice has the power to do. That is the ultimate explanation, there is nothing more to say.

As Frijof Capra notes in the Tao of Physicscontemporary particle physics has become a search for
the Holy Grail of a fundamental atom-like particle which is the indestructible ingredient of every
physical structure. But why should there be any such particle? As the presocratic philosopher
Heraclitus argued, if you posit the Logos,physical law as the fundamental thing, there is no need to
posit fundamental stuff.Or as Capra argues, an alternative explanation of the photographs of
particles smashing into ever smaller bits is that allthat is constant is the repeated and repeatable
pattern: in Aristotle's terms, the form.

Geoffrey Klempner