As an instance
of the difference applying to the genus I give man and horse (for
mankind has a longer life than the horse), while within the species
there is the difference between man and man; for of men also some
are long-lived, others short-lived, differing from each other in
respect of the different regions in which they dwell. Races inhabiting
warm countries have longer life, those living in a cold climate live a
shorter time. Likewise there are similar differences among individuals
occupying the same locality.
2
In order to find premisses for our argument, we must answer the
question, What is that which, in natural objects, makes them easily
destroyed, or the reverse? Since fire and water, and whatsoever is
akin thereto, do not possess identical powers they are reciprocal
causes of generation and decay. Hence it is natural to infer that
everything else arising from them and composed of them should share in
the same nature, in all cases where things are not, like a house, a
composite unity formed by the synthesis of many things.
In other matters a different account must be given; for in many
things their mode of dissolution is something peculiar to
themselves, e.g. in knowledge and health and disease. These pass
away even though the medium in which they are found is not destroyed
but continues to exist; for example, take the termination of
ignorance, which is recollection or learning, while knowledge passes
away into forgetfulness, or error.
Pages:
1
2
3
4
5
6
7
8
9
10