Substance theory

Substance Theory is a theory that says that things are made of substances. A substance is something that has its own properties, like color, shape, or size. This means that an apple, for example, has its own properties: it has a red color, it is round, and it is a certain size. This is different from the idea that an apple is just a combination of different parts put together, like an apple core, an apple stem, and some apple skin. Substance Theory instead says that an apple is a single thing, with its own properties, and that when you put all of the parts together it makes an apple.