From these thinkers, then, one might think that there is only a single cause, that said in the form of matter. But as they continued in this way, the facts themselves guided them and forced them to seek further. For even if, as much as you like, all coming to be and destruction are from some simple thing, or from several, why does this happen and what is the cause? For indeed it cannot be that the substrate itself forces itself to change. I mean that, for instance, neither wood nor bronze is the cause of either of them changing, neither does wood make a bed, or bronze a statue, but there is some other cause of the change. And to seek for this is to seek for the second kind of principle, as we would say, that from which comes the beginning of the change.
ARISTOTLE (1998, p. 14)
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