Home | Texts by category | | Quick Search:   
Works by Aristotle
Pages of On The Generation Of Animals

Previous | Next

On The Generation Of Animals   

carry the material to the workman. For by reason of weakness in such
males Nature is not able to do anything by any secondary means, but
the movements imparted to the material are scarcely strong enough when
Nature herself watches over them. Thus here she resembles a modeller
in clay rather than a carpenter, for she does not touch the work she
is forming by means of tools, but, as it were, with her own hands.


In all animals which can move about, the sexes are separated, one
individual being male and one female, though both are the same in
species, as with man and horse. But in plants these powers are
mingled, female not being separated from male. Wherefore they generate
out of themselves, and do not emit semen but produce an embryo, what
is called the seed. Empedocles puts this well in the line: 'and thus
the tall trees oviposit; first olives...' For as the egg is an embryo,
a certain part of it giving rise to the animal and the rest being
nutriment, so also from a part of the seed springs the growing
plant, and the rest is nutriment for the shoot and the first root.

In a certain sense the same thing happens also in those animals
which have the sexes separate. For when there is need for them to
generate the sexes are no longer separated any more than in plants,
their nature desiring that they shall become one; and this is plain to
view when they copulate and are united, that one animal is made out of

It is the nature of those creatures which do not emit semen to
remain united a long time until the male element has formed the
embryo, as with those insects which copulate. The others so remain
only until the male has discharged from the parts of himself
introduced something which will form the embryo in a longer time, as
among the sanguinea. For the former remain paired some part of a
day, while the semen forms the embryo in several days. And after
emitting this they cease their union.

And animals seem literally to be like divided plants, as though
one should separate and divide them, when they bear seed, into the
male and female existing in them.

In all this Nature acts like an intelligent workman. For to the
essence of plants belongs no other function or business than the
production of seed; since, then, this is brought about by the union of
male and female, Nature has mixed these and set them together in
plants, so that the sexes are not divided in them. Plants, however,
have been investigated elsewhere. But the function of the animal is
not only to generate (which is common to all living things), but
they all of them participate also in a kind of knowledge, some more
and some less, and some very little indeed. For they have
sense-perception, and this is a kind of knowledge. (If we consider
the value of this we find that it is of great importance compared with
the class of lifeless objects, but of little compared with the use
of the intellect. For against the latter the mere participation in
touch and taste seems to be practically nothing, but beside absolute
insensibility it seems most excellent; for it would seem a treasure to
gain even this kind of knowledge rather than to lie in a state of
death and non-existence.) Now it is by sense-perception that an
animal differs from those organisms which have only life. But since,
if it is a living animal, it must also live; therefore, when it is
necessary for it to accomplish the function of that which has life, it
unites and copulates, becoming like a plant, as we said before.

Testaceous animals, being intermediate between animals and plants,
perform the function of neither class as belonging to both. As

Previous | Next
Site Search