[1071a] [1] And therefore all things have the same causes, because without substance there can be no affections and motions. Next we shall see1 that these causes are probably soul and body, or mind, appetite and body.2 Again, there is another sense in which by analogy the principles are the same viz. actuality and potentiality; but these are different for different things, and apply to them in different ways.For in some cases the same thing exists now actually and now potentially; e.g. wine or flesh or man (actuality and potentiality also fall under the causes as already described; for the form exists actually if it is separable, and so does the compound of form and matter, and the privation, e.g. darkness or disease; and the matter exists potentially, for it is this which has the potentiality of becoming both3;but the distinction in virtue of actuality and potentiality applies in a different sense to cases where the matter of cause and effect is not the same, in some of which the form is not the same but different. E.g., the cause of a man is (i) his elements: fire and earth as matter, and the particular form; (2) some external formal cause, viz. his father; and besides these (3) the sun and the ecliptic,4 which are neither matter nor form nor privation nor identical in form with him, but cause motion.

Further, we must observe that some causes can be stated universally, but others cannot.The proximate principles of all things are the proximate actual individual and another individual which exists potentially.5 [20] Therefore the proximate principles are not universal. For it is the particular that is the principle of particulars; “man” in general is the principle of “man” in general, but there is no such person as “man,” whereas Peleus is the principle of Achilles and your father of you, and this particular B of this particular BA; but B in general is the principle of BA regarded absolutely.Again, even if the causes of substances are universal, still, as has been said,6 different things, i.e. things which are not in the same genus, as colors, sounds, substances and quantity, have different causes and elements, except in an analogical sense; and the causes of things which are in the same species are different, not in species, but because the causes of individuals are different: your matter and form and moving cause being different from mine, although in their universal formula they are the same.

As for the question what are the principles or elements of substances and relations and qualities, whether they are the same or different, it is evident that when the terms “principle” and “element” are used with several meanings they are the same for everything; but when the meanings are distinguished, they are not the same but different; except that in a certain sense they are the same for all. In a certain sense they are the same or analogous, because (a) everything has matter, form, privation and a moving cause; (b) the causes of substances may be regarded as the causes of all things, since if substances are destroyed everything is destroyed; and further (c) that which is first in complete reality7 is the cause of all things.In another sense, however, proximate causes are different; there are as many proximate causes as there are contraries which are predicated neither as genera nor with a variety of meanings8; and further the particular material causes are different.

1. See Introduction.
2. Aristotle is thinking of animals and human beings, which are substances in the truest sense.
3. i.e., of acquiring either of the contrary qualities distinguished by the form and the privation
4. The sun, moving in the ecliptic, approaches nearer to the earth in summer, causing generation, and recedes farther from the earth in winter, causing destruction. Cf. Aristot. Met. 12.6.10 n., Aristot. De Gen. et Corr. 336a 32.