a. Action is not anything Absolute

27. To understand this difficulty about whether action, in the way it is distinguished from relation, belongs to God intrinsically or extrinsically in general, and thereby whether it belongs specifically in the matter at issue, there is need to consider the idea of ‘action’ as it is set down to be distinct from ‘relation’. For ‘action’ cannot be set down as something absolute, in the way it is one of the distinct categories among the ten categories. The proof is that it would be something new, and then two unacceptable consequences would follow.

28. One is general, that there would an action for action, and so ad infinitum; the reason is that of the Philosopher in Physics 5.2.225b13-14, whereby he proves that there cannot be a motion for action. And how this result holds is plain, because every new form can have an action for it, since the form is not from itself or from nothing, therefore it is from an agent.

29. The second unacceptable consequence is particular, namely by division, for in what category would the action be put? If it is in the agent then every agent would be changed in its absolute form before the thing acted on was changed by it, for the thing acted on is not changed save by an agent already possessing action - but for the agent to possess the action, since the action is a new absolute form, it would have to change so as to possess it.

30. The response is made that it would change, because change is an act of what is in passive potency, while an active thing is, before it acts, in active potency; and so its passing from this potency into act is not motion or change.

31. On the contrary: if action is an absolute and new form in an agent, the agent must have some receptivity for that form, because the new form is not self-subsistent (for then nothing would be formally an agent by the new form, just as neither is something said to be formally a quantum by a quantity separate from it); but something receptive has some receptive or passive potency with respect to what it is receptive of; therefore the active thing will, before the action, be in passive potency to action. And because it has this passive potency sometimes without the form and sometimes with the form, it is properly changed; so the conclusion intended follows, that an agent properly undergoes a change.

32. As for the addition that action is the act of an active potency [n.30], this indeed is true simply, but it is difficult to save this fact on the hypothesis, namely on the supposition that action is something absolute in the agent. For it cannot belong to the active power as receptive, for this is contrary to the idea of a receptive or passive power. Nor can it belong to the active power as elicitive; the proof is that it does not come from it because it belongs to its being as it is active, for then the active thing would actively change itself for this action by a prior absolute form, and then there would be a further question as to what changes it for this prior action, and so on ad infinitum.

33. But if one does hold this hypothesis one must say that action, although it belongs in some way to active potency, is yet the act of some passive potency, for this is universally true of every form that is not separate from the receptive thing.

34. If it also be said, against this hypothesis, that action is in the thing acted on, then something unacceptable follows, namely that nothing acted on can be acted on according to a form in the category of quantity or quality without being acted on at the same time, or perhaps acted on prior in nature, according to a form in another category, namely according to the action that is posited in it as another and absolute form, a form different from quantity and quality. This consequent seems unacceptable, especially about prior and posterior forms, because the subject cannot be acted according to an absolute prior form unless it is acted on according to a posterior form that will not be a proper being acted on by the prior form (the thing is plain, because whiteness can remain in a subject after the action that makes it so is over).

35. So the negative proposition is therefore proved, that ‘action as it is posited to be a new category distinct from other categories is not a new absolute form [n.27], either in the agent or the patient’.