THAT OF SPIRITUAL AND CORPOREAL SUBSTANCES
THERE CANNOT BE ONE MATTER
32.--We may further conclude from this argument that there cannot be one matter for both spiritual and corporeal substances. For if both have a single and common matter, there must be understood in it a distinction prior to the difference of forms, namely, a distinction of spirituality and corporeity. This disposition cannot be according to a division of quantity because the dimensions of quantity are not found in spiritual substances. Accordingly, it remains that this distinction is either according to forms or dispositions or according to matter itself; and since it cannot be according to forms and dispositions to infinity, we must finally come back to this, that the distinction is present in matter according to matter itself. Therefore the matter of spiritual substances will be absolutely other than the matter of corporeal substances.
33.--Again, since it is the property of matter as such to receive, if the matter of spiritual and corporeal substances is the same, then it is necessary that the mode of reception be the same in both. The matter of corporeal things, however, receives the form in a particular way, that is, not according to the common nature of form. Nor does corporeal matter act in this way insofar as it is subject to dimensions or to a corporeal form, since corporeal matter receives the corporeal form itself in an individual way. Accordingly, it becomes clear that this befits such a matter from the very nature of the matter which, since it is the lowest reality, receives form in the weakest manner; for reception takes place according to the mode of the receiver. Thereby matter, by receiving that form in a particular way, falls short in the greatest degree of that complete reception of form which is according to the totality of the form. Now it is clear that every intellectual substance receives the intellected form according to its totality, or otherwise it would not be able to know it in its totality. For it is thus that the intellect understands a thing insofar as the form of that thing exists in it. It remains therefore that if there be a matter in spiritual substances, it is not the same as the matter of corporeal things, but much nobler and finer, since it receives form according to its totality.
34.--Again, as we consider the matter further, it becomes clear that a given being has a higher place among beings according as it has a greater share in "to be". It is clear, however, that since being is divided by potency and act, act is more perfect than potency and has a greater share in "to be". For we do not say without qualification that what is in potency, is; we say this only of what is in act. It is therefore necessary that that which is higher among beings approach more closely to act, and that what is lowest among beings, be nearer to potency. And since the matter of spiritual substances cannot be the same as the matter of corporeal substances but is much higher as has been shown, it must be separated from the matter of corporeal substances according to the difference of potency and act.
Now according to the opinion of Aristotle and Plato, the matter of corporeal things is pure potency. It remains therefore that the matter of spiritual substances is not pure potency but is something actual existing in potency. I am not saying "some thing actual existing in potency" as though I meant some thing composed of act and potency, because either we should have to proceed to infinity or we should have to arrive at something which was a being only in potency; and since this being is the lowest among beings and consequently can receive existence in a way which is weak and particularized, it cannot be the prime matter of a spiritual and intellectual substance. It remains therefore that the matter of a spiritual substance is in such wise a being in act that it be a subsisting act or form, just as the matter of corporeal things is said to be a being in potency for the reason that it is the very potency which is subject to forms.
35.--Furthermore, whenever matter is posited as an actual being, it makes no difference whether we call it the matter or the substance of a thing. For thus the ancient Natural Philosophers, who held that the first matter of corporeal things was some actual being, said that matter was the substance of all things in the same way that the substance of artificial things is nothing other than their matter. Therefore, if the matter of spiritual substances cannot be only some potential being but is some actual being, then the matter itself of spiritual beings is their substance. And in this case, there is no difference whether we posit matter in spiritual substances or whether we hold that simple spiritual substances are not composed of matter and form.
Furthermore, act is by nature prior to potency and form prior to matter and since potency depends in its existence on act and matter depends on form, whereas form according to its proper nature does not depend on matter for its existence, neither does act, (for that which is by nature prior does not depend upon that which is by nature subsequent);--since this is the case, if there are some forms which cannot exist without matter, this befits them not because they are forms, but because they are such forms, namely, imperfect forms which cannot exist through themselves of their own accord but need the foundation of matter.
36.--Now in all classes of being, prior to every thing imperfect, there is found something perfect. For example, if there is fire in a foreign matter upon which the fire according to its nature does not depend, then it follows that the fire is not supported in the foreign matter. Therefore above the forms received in matter, there are certain self-subsisting forms which are spiritual substances not composed of matter and form. This fact also appears among the lowest of the spiritual substances, namely souls, on the assumption that they are united to bodies as forms. For it is impossible that that which is composed of matter and form be the form of some body. For to be the form of some being is to be the act of that being. Hence no part of that which is the form of some being can be matter, which is pure potency.