on the other hand, says:
a) that everything changes (“all things flow”), and
b) that our sensory perceptions are reliable.
***
Philosophers could hardly disagree more than that! But who was right? It
fell to Empedocles (c. 490-430 B.C.) from Sicily to lead the way out of the
tangle they had gotten themselves into.
He thought they were both right in one of their assertions but wrong in
the other.
Empedocles found that the cause of their basic disagreement was that
both philosophers had assumed the presence of only one element. If this
were true, the gap between what reason dictates and what “we can see with
our own eyes” would be unbridgeable.
Water obviously cannot turn into a fish or a butterfly. In fact, water
cannot change. Pure water will continue to be pure water. So Parmenides
was right in holding that “nothing changes.”
But at the same time Empedocles agreed with Heraclitus that we must
trust the evidence of our senses. We must believe what we see, and what we
see is precisely that nature changes.
Empedocles concluded that it was the idea of a single basic substance
that had to be rejected. Neither water nor air alone can change into a
rosebush or a butterfly. The source of nature cannot possibly be one single
“element.”
Empedocles believed that all in all, nature consisted of four elements, or
“roots” as he termed them. These four roots were earth, air, fire, and wafer.
All natural processes were due to the coming together and separating of
these four elements. For all things were a mixture of earth, air, fire, and water,
but in varying proportions. When a flower or an animal dies, he said, the four
elements separate again. We can register these changes with the naked eye.
But earth and air, fire and water remain everlasting, “untouched” by all the
compounds of which they are part. So it is not correct to say that “everything”
changes. Basically, nothing changes. What happens is that the four elements
are combined and separated—only to be combined again.
We can make a comparison to painting. If a painter only has one color—
red, for instance—he cannot paint green trees. But if he has yellow, red, blue,
and black, he can paint in hundreds of different colors because he can mix
them in varying proportions.
An example from the kitchen illustrates the same thing. If I only have
flour, I have to be a wizard to bake a cake. But if I have eggs, flour, milk, and
sugar, then I can make any number of different cakes.
It was not purely by chance that Empedocles chose earth, air, fire, and
water as nature’s “roots.” Other philosophers before him had tried to show
that the primordial substance had to be either water, air, or fire. Thales and
Anaximenes had pointed out that both water and air were essential elements
in the physical world. The Greeks believed that fire was also essential. They
observed, for example, the importance of the sun to all living things, and they
also knew that both animals and humans have body heat.
Empedocles might have watched a piece of wood burning. Something