Subsequently, Boethius refined the word to mean "an individual substance of a rational nature."

When embodied, a human person is an "individual substance in the category rational animal."

As to our knowledge of the material world: whatever exists is itself, an incommunicable, individual substance.

Even the real essences of individual substances imply potential sorts.

The term particular is also used as a modern equivalent of the Aristotelian notion of individual substance.

Each individual substance absorbs specific different wavelengths of visible light.

Averroes, following Aristotle, holds that individual existing substances are primary.

Aristotle's "individual substances" are atomic in the same sense.

What makes an individual substance - a man, a tree, a planet - real is a distinct act, a "to be", which actuates its unity.

Both individual substances and the final product have to be produced in accordance with good manufacturing practice.