Aristotle on Metaphysics(2004) - Bibotu.com

242 THE SEARCH FOR PRIMARY BEINGx, is what this very thing, x, is. And the essence of a thing, x, either is thekind to which the thing belongs or certainly it determines the kind towhich the thing belongs. Thus, at the opening of VII. 11, <strong>Aristotle</strong> pointsout that it is not part of the essence of a spherical material thing that isactually generated out of bronze to be generated out of bronze; for thereare also spherical material things that are generated out of stone, wood,etc. (1036 a 31–34). He adds that even if it should happen that all sphericalmaterial things are generated out of bronze, still it would not be part of theessence of spherical material things to be generated out of bronze(1036 a 34–b3). Intriguingly and suggestively, he adds that although humanbeings are actually generated out of flesh and bones, being generated out offlesh and bones is not part of the essence of a human being (1036 b 3–7);for the same kind of thing, a human being, could have been generated outof a different matter. This is intriguing and suggestive, not least because<strong>Aristotle</strong> knew nothing of artificial intelligence. Evidently he thinks that thisclaim, i.e. the claim that human beings could have been generated out of adifferent matter than the matter out of which they are actually generated,is one that we will naturally find plausible. Indeed, we may find itplausible, as in fact we appear to do when we speculate whether there maybe human beings on other planets, e.g. Mars, although we also think that,if there are Martians, their material constitution is likely to be differentfrom ours. So we may well share <strong>Aristotle</strong>’s intuition that it is not part ofthe essence of a material thing to be generated out of the matter that it isactually generated out of; and that, therefore, the matter of a materialthing is not part of its essence.Still, such intuitions can be questioned, so we may still ask why <strong>Aristotle</strong>thinks that the matter of a material thing is not part of the essence of thatthing. The reason, it appears, is that he thinks that the matter of aparticular material thing, e.g. a human being, contributes only to theexplanation of how the thing comes to be and passes away, i.e. how it isgenerated and destroyed; it does not contribute to the explanation of whythe thing is the very thing it is. For the matter of a material thing is,exactly, that out of which (to ex hou) the thing comes to be and that intowhich it passes away (see especially VII. 10, 1035 a 17f.; see also VII. 1,especially 1032 b 32f.). We thus saw that <strong>Aristotle</strong> argues (in VII. 8) thatwhen a material thing, e.g. a bronze sphere, is involved in its own processof generation, the only thing that changes in this process is the matter ofthe material thing; for example, the bronze changes shape when it isshaped into a bronze sphere. By contrast, the form of the thing that isgenerated, i.e. the principle which explains why the matter is generatedinto the very thing into which it is generated, e.g. into a bronze sphere,