An Argument for the Aristotelian Theory The Aristotelians...

An Argument for the Aristotelian Theory The Aristotelians, who believe in prime matter as substance devoid of actuality, have offered for their position two arguments which were originally close to one another: one of these is called the ‘proof from potentiality and actuality’ and the other is called the ‘proof from union and separation.’ They may be summarized as follows.

There are transformations in bodies which are unions and separations, as well as substantial and accidental changes; for example, a continuous unified body may be transformed into two separate bodies, water changes into steam, the seed of a tree changes into a tree. Without a doubt, these various changes do not take place in such a way that the first substance is completely obliterated and one or more other existents are brought into existence from pure nothingness.

Rather, certainly something from the prior existent remains in the later existent. However, that which remains is not the form and actuality of the prior existent; hence there is no other alternative but that another substance exists in them which preserves the existential relation between them. This in itself essentially and necessarily must have no actuality, and for this reason, it accepts various sorts of actuality.

In this way it is established that there is a substance which has no actuality, and which is characterized by the acceptance of forms, and, in philosophical terms, it is called pure potentiality. In other words, every corporeal existent possesses two aspects: one is the aspect of actuality and the possession of properties, and the other is the aspect of potentiality and privation in relation to future actualities.

These two aspects are different from each other, and so, every corporeal existent is composed of two different objective things. And since it is not possible for the existence of a substance to be composed of two accidents or of a substance and an accident, there is no other choice but that they must be composed of two substantial parts, one which is the aspect of actuality, and the other the aspect of potentiality.

This argument can also be put in the following form, or the following may be considered as another argument. It is possible for all bodies to change into another kind of body, such as the change of one element into another, or the transformation of one or more elements into minerals, vegetables or animals (potentiality and actuality).