It has been clearly shown by us in the foregoing that of things there
are some which have one thing in common and differ in an other, in that
the one in common is other than the one differed in. Then we found
compound ensouled bodies--I mean possessing souls--to have agreed
and differed in the properties both of their impulsion and their
perception. As to impulsion, they agree and differ, in that one and all
of them has in common that they move in quantity the motion of growth;
and they differ, in that one sett among them moves, together with that
growth, in local motions according to the will; and one other sett
among them does not so move, such as plants. Likewise living beings
have in common that they are both sentient and perceptive, up to a
certain sort of sensuous perception; and then afterwards they differ in
that one sett among them perceives, together with that sort of sensuous
perception, by intellectual perception; and one other sett among them
does not so perceive, such as the ass and the horse. We further found
the power of impulsion to be more widely embracing than the power of
perception, in that we found plants to lack the latter utterly. Hence
we knew for certain that the faculty in which the animal agrees with
the plant is more general than this perceptive faculty, and than the
impelling faculty which is in the animal; and each one of them is more
general than the speaking (rational) faculty, which belongs to man.
Thus then, the spiritual faculties come forth (or stand out) before
us set and ranged, in respect of the common and the peculiar, i.e.,
according to the general and special[C], under three classes or
ranks:[D]
The first of which is known as the plant or vegetable power, on account
of the participation therein of the animal and plant;
The second is known as the animal power;
The third, as the speaking power, or rational faculty.
Therefore, the primary parts of the soul, in contemplating it from the
standpoint of its powers, are three.