SPROUL: In addressing the problem of dualism, and in trying to bring everything into unity,
Aristotle developed what we call his “theory of substance.”
Plato had his theory of ideas. Aristotle had his theory of substance. And what
Aristotle meant by this is that all individual entities, everything that exists in this world,
exists as a primary substance. Now, he said two very important things
about these individual entities. Remember the concrete entities
that we find in this world according to Plato were called “receptacles.” They were imperfect
copies of the real ideas that exist in this other world, in the ideal world. For Aristotle,
the individual objects, entities, and things that we encounter in this world are real. And they are
substantial. And every substance is comprised of two aspects, or two things: matter
and form. Sometimes Aristotle’s philosophy is referred to as the “theory of form.” And, I would
say that there is no element of Aristotle’s thought that has been more perplexing to
later philosophers, who have sought to analyze and understand the depths of his thinking,
than his concept of form. And I’ll just mention in passing that even to this day, there is an ongoing
debate among experts in Aristotelian philosophy about exactly what Aristotle meant by his concept
of form. But in this idea of substance that he distinguishes between matter and form,
he finds the resolution of the ancient problem of “being” and “becoming.” Now, remember in Plato,
“being” is found in the idea up here, and “becoming”
in the receptacle or material things down here. For Aristotle, “being” and “becoming” are found
in each individual entity. Every substance that there is, contains within it both matter
and form. “Form” is that which gives the object, or the subject, its being.
Without participating in being, without containing being,
whatever is couldn’t be, so that you couldn’t have any real things or real
objects unless there was some being within them. But also, things in this world, physical things,
“material things” as we know them, also have elements of change, elements of “becoming.” That
is part of the matter of a thing. Let me see if I can illustrate this in our own contemporary ways
of thinking. We talk as Christians about a human person as being made up of two
distinct substances. This is what we call a “substantial dichotomy,”
a duality. This is not a dualism, but a duality of body and soul. And if you don't have a body,
then something is lost from your entity, and if you have no soul you couldn’t live at all. So,
for Aristotle, within each object, there was matter and form. The “form” is the eternal
being and the “matter” is that which is changing and is the locus of potential.