  Indeed, the Physics will later submit its own list of categories. That list is slightly reduced—it has seven or eight elements, depending on whether we include or exclude  time.[10]    The reduced list also concludes with the claim that there are three kinds of motion, plus the additional kind of substantial  change.[11]  That is to say, even where Aristotle enumerates a fairly complete list of categories, he will not have motions in every one of these categories, and he is not content to relegate motions to the categories of action and  passion.[12]   But this is a context where Aristotle stresses another issue: he is not interested in assigning a separate ontological niche for motions—regardless of whether that might or might not have been a feasible task within the categorization of entities. Here Aristotle is more intent on characterizing the ontological links which motions have to entities falling into different categories, and to find a general matrix of undergoing and effecting change. This happens in several steps. First Aristotle claims that changes of relations are not changes in their own right; rather they are accidental, as they occur also in entities in which no change occurs at all, if the entity which they stand in relation to undergoes some  change.[13]  After these considerations the crucial two categories of action and passion are eliminated: As there are no motions of motions, we can set aside action and passion (items (7) and (8) in the  Categories).[14]  This leaves us with the shorter list of relevant categories, (1) substance, (2) quality, (3) quantity, and (4)  place.[15] 