ABSTRACT
To the class of causal relations102 there belongs everything that somehow conditions the being of a thing or is conditioned by it. Thus this class includes also parts as such (‘partial causes’), since the whole could not be without the part. One has often called this the material cause. The class of parts also includes the substance which as subject is contained in its accidents as part, and it also includes every accident that underlies another accident. It does not however, when precisely considered, include a logical part, since the universal is individuated in the thing.103 Included further is that which is continuous (‘continual cause’). In the case of what is spatial, continual causation is (where we are not dealing with contiguity) a mutual causation between a boundary and what it bounds. The class of causal relations includes also the efficient cause, to which is related that from out of which something else develops on coming into existence. Some would also like to include here that which has the power to receive something in itself, as a precondition of realisation, while others might want to count this among the partial causes.104 A special mention is also required of what takes place according to the law of inertia and other kinds of persistence.
