God as Pure Act, Part V
The relations between the various aspects of incomplete acts
Every incomplete act has three aspects: that to which, that by which, and that out of which. All three are necessary for an incomplete act, so much so that if any one of these aspects were to cease being, the incomplete act would immediately cease to be. If the completion ceased to be (that to which) the act would immediately lose any reason to be called “incomplete”, for it was only named such by its completion. That the thing completing is necessary for the incomplete act is too obvious to mention (the “completing thing”can be either that by which, or that out of which). If we lack either things to build out of, or builders, we won’t have the act of building either.
There is also a relation between all three aspects as regards moving and being moved*. That out of which something is being completed (the materials) is wholly being moved; that by which a thing is being completed (the worker) both is moving the materials and being moved by the completion, and the completion is moving the builder and is itself not moving. The sense of “moving” is not absolutely identical in each case, but there is a proportion between them- we can be moved by ropes, and moved by beauty. As there is a relatin of moving and being moved, there is also a relation of order.
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Just Thomism 