Introduction to Classical Christian Metaphysics – Part 2

Post Author: Bill Pratt

In part 1 we introduced the metaphysical principles of act and potency. In part 2 we introduce the metaphysical principles of form and matter.

Ordinary objects of our experience are composed of two metaphysical principles – form and matter.  Edward Feser explains these principles, again using a rubber ball:

The rubber ball of our example is composed of a certain kind of matter (namely rubber) and a certain kind of form (namely the form of a red, round, bouncy object). The matter by itself isn’t the ball, for the rubber could take on the form of a doorstop, an eraser, or any number of other things. The form by itself isn’t the ball either, for you can’t bounce redness, roundness, or even bounciness down the hallway, these being mere abstractions. It is only the form and matter together that constitute the ball.

The form thus determines what a thing is.  In this sense, the form of an object is sometimes called its essence or nature.  Feser explains that matter

will always have some substantial form or other, and thus count as a substance of some kind or other; . . . The notion of prime matter is just the notion of something in pure potentiality with respect to having any kind of form, and thus with respect to being any kind of thing at all. . . . [W]hat is purely potential has no actuality at all, and thus does not exist at all.

It should be noted that the Aristotelian-Thomistic notion of “form” is not the same as Plato’s notion.  Plato held that forms only exist in a realm wholly apart from the material world.  For Aquinas, the forms are instantiated in individual substances which exist in the world.  Apart from substances, forms are abstractions, but they are nonetheless real things, not mere human inventions.

Feser comments, “When we grasp [forms such as] ‘humanity,’ ‘triangularity,’ and the like, what we grasp are not mere inventions of the human mind, but are grounded in the natures of real human beings, triangles, or what have you.”

In part 3 we will look at the famous four causes.