Perhaps it would be better if matter and form were...

Perhaps it would be better if matter and form were considered to be two kinds of material substances, with the explanation that prime matter is inseparable from corporeal form, and that the combination of them is called ‘body.’ The main problem is that the existence of a substance which essentially lacks any kind of actuality cannot be established, and it seems that, with regard to this problem, the correct position is that of Shaykh al-Ishrāq, ‘Allāmah Ṭūsī and other philosophers who have denied the existence of this sort of substance.

With the denial of prime matter as a substance lacking any sort of actuality, no room remains for establishing the existence of another sort of substance which is the first form for prime matter and that which grants it actuality, for according to this view, which is attributed to the Platonists, the first matter is a substance possessing actuality, but which is not composed of matter and form.

However, new forms occur in it either alternatively or simultaneously, such that a specific elemental form appears in it, and with its removal, it is replaced by another elemental form. However, the elemental form comes into existence simultaneously with the mineral form or vegetable form, and altogether they are incarnated in the substance of the body, that is, their parts correspond precisely to one another.

However, through all these alterations, the body always remains as a substance which possesses actuality, despite the denials by some philosophers that the new forms are substances. These philosophers only accept them as accidents for the body.

Given the denial of matter without actuality, and the acceptance of the forms of species, as kinds of substance, corporeal substances may be divided into two general kinds: one is that of a substance which does not need a location at which to be incarnated, and this is the same as body; the other is a substance which needs another substance to be incarnated in it and impressed in it, and this substance is the form of a species, such as the elemental, mineral and vegetable forms.

However, with the denial that these sorts of forms are substances, the corporeal and material substances will be confined to bodies. This seems to indicate the difference between primary and secondary substances in Aristotle. The primary substances are not incarnated, only the secondary ones are.