On this point, a group of philosophers, such as Ibn Sīnā and his like, took the opposite position: they regarded all forms as substances, just as the former regarded all forms as accidents.

These philosophers examined manufactured objects—such as a ring, a dirham, a sword, a bed, a house, a bull, and other things that human beings assemble and shape. They found them to be composed of matter, such as silver, which they also call hayūlā. In their language, hayūlā means the substratum, and they employ the word according to their own specialized usage, just as Arabic speakers employ Arabized vocabulary. Thus, these manufactured objects are composed of matter, which is the substratum, and form, which is the particular shape. This observation is correct.

They then claimed that the forms of animals, plants, and minerals likewise have matter that constitutes their hayūlā, and that fire, air, and earth also have matter that constitutes their hayūlā.

Some of them said that all bodies have a common matter constituting their hayūlā. They distinguished three levels of hayūlā: artificial, natural, and universal.

They disagreed over whether universal matter can exist apart from forms, so that hayūlā would be devoid of forms. There were two positions on this: affirmation of such matter devoid of forms is attributed to the followers of Plato, while its denial is the position of the followers of Aristotle.