They recognized four categories...
* substance (ὑποκείμενον) The primary matter, formless substance, (ousia) which makes up things.
* quality (ποιόν) The way in which matter is organized to form an individual object. In Stoic physics, a physical ingredient (pneuma: air or breath) which informs the matter.
* somehow disposed (πως ἔχον) Particular characteristics, not present within the object, such as size, shape, action, and posture.
* somehow disposed in relation to something (πρός τί πως ἔχον) Characteristics which are related to other phenomenae, such as the position of an object within time and space relative to other objects.