Unit 5: Core Concepts in Metaphysics

Concept of Substance

Substance is one of the most central and disputed concepts in metaphysics. It refers to the "ultimate stuff" of reality, the fundamental "thing" that "stands under" (sub-stare) and supports all of an object's properties.

Substance is traditionally defined as that which can exist *independently* on its own, and which persists through change. It is the "owner" of properties (qualities, attributes).

Example: An Apple

• We perceive its *properties*: "red," "round," "sweet," "hard."
• But what is the "it" that *has* these properties? We call this "it" the substance.
• The properties can change (the apple can become "brown" and "soft"), but we still assume the underlying "substance" (the apple itself) remains the same.

Philosophical Views on Substance:

Philosopher	View on Substance
Aristotle	A concrete, individual thing (e.g., "this man" or "this horse"), a composite of Form and Matter.
Descartes (Rationalist)	There are three substances: God (the only true, independent substance), Mind (whose essence is thinking), and Matter (whose essence is extension/size).
Spinoza (Rationalist)	There is only one infinite substance, which he called "God" or "Nature." Mind and matter are just two "attributes" of this one substance.
Locke (Empiricist)	We must *assume* a substance exists as an "I know not what" (a "substratum") to support the qualities we perceive, but we can never *experience* it directly.
Hume (Empiricist)	Rejects substance. Since all knowledge is from experience, and we only ever experience a "bundle" of properties (red, sweet, round), we have no basis for believing in an *extra* "thing" called substance. "Substance" is just a word we use for this bundle.