a man carries with it the truth of the proposition that he is,
and the implication is reciprocal: for if a man is, the
proposition wherein we allege that he is true, and conversely, if
the proposition wherein we allege that he is true, then he is.
The true proposition, however, is in no way the cause of the
being of the man, but the fact of the man's being does seem
somehow to be the cause of the truth of the proposition, for the
truth or falsity of the proposition depends on the fact of the
man's being or not being.

Thus the word 'prior' may be used in five senses.

Part 13

The term 'simultaneous' is primarily and most appropriately
applied to those things the genesis of the one of which is
simultaneous with that of the other; for in such cases neither is
prior or posterior to the other. Such things are said to be
simultaneous in point of time. Those things, again, are
'simultaneous' in point of nature, the being of each of which
involves that of the other, while at the same time neither is the
cause of the other's being. This is the case with regard to the
double and the half, for these are reciprocally dependent, since,
if there is a double, there is also a half, and if there is a
half, there is also a double, while at the same time neither is
the cause of the being of the other.

Again, those species which are distinguished one from another and
opposed one to another within the same genus are said to be
'simultaneous' in nature. I mean those species which are