Kitap 2
7
The necessity of what we are arguing is clear from AnalyticsCf. Aristot. Anal. Post. 1.1; at present we cannot either deny or affirm anything definitely except just this. Supposing there were no further cause of the triangle’s having the property stated, then the triangle would be a sort of first principle or cause of the later stages.
8
Hence if in fact there are among existing things some that admit of the opposite state, their first principles also must necessarily have the same quality; for of things that are of necessity the result is necessary, albeit the subsequent stages may possibly happen in the opposite way. And the things that depend on men themselves in many cases belong to this class of variables, and men are themselves the first principle of things of this sort.
9
Hence it is clear that all the actions of which a man is the first principle and controller may either happen or not happen, and that it depends on himself for them to happen or not, as he controls their existence or non-existence. But of things which it depends on him to do or not to do he is himself the cause, and what he is the cause of depends on himself.
