copulate, for the females manifestly insert this from below into the
males above, not in all cases, but in most of those observed. Hence it
seems clear that, when the males do emit semen, then also the cause of
the generation is not its coming from all the body, but something else
which must be investigated hereafter. For even if it were true that it
comes from all the body, as they say, they ought not to claim that
it comes from all parts of it, but only from the creative part- from
the workman, so to say, not the material he works in. Instead of that,
they talk as if one were to say that the semen comes from the shoes,
for, generally speaking, if a son is like his father, the shoes he
wears are like his father's shoes.
As to the vehemence of pleasure in sexual intercourse, it is not
because the semen comes from all the body, but because there is a
strong friction (wherefore if this intercourse is often repeated
the pleasure is diminished in the persons concerned). Moreover, the
pleasure is at the end of the act, but it ought, on the theory, to
be in each of the parts, and not at the same time, but sooner in
some and later in others.
If mutilated young are born of mutilated parents, it is for the same
reason as that for which they are like them. And the young of
mutilated parents are not always mutilated, just as they are not
always like their parents; the cause of this must be inquired into
later, for this problem is the same as that.
Again, if the female does not produce semen, it is reasonable to
suppose it does not come from all the body of the male either.
Conversely, if it does not come from all the male it is not
unreasonable to suppose that it does not come from the female, but
that the female is cause of the generation in some other way. Into
this we must next inquire, since it is plain that the semen is not
secreted from all the parts.
In this investigation and those which follow from it, the first
thing to do is to understand what semen is, for then it will be easier
to inquire into its operations and the phenomena connected with it.
Now the object of semen is to be of such a nature that from it as
their origin come into being those things which are naturally
formed, not because there is any agent which makes them from it as
simply because this is the semen. Now we speak of one thing coming
from another in many senses; it is one thing when we say that night
comes from day or a man becomes man from boy, meaning that A follows
B; it is another if we say that a statue is made from bronze and a bed
from wood, and so on in all the other cases where we say that the
thing made is made from a material, meaning that the whole is formed
from something preexisting which is only put into shape. In a third
sense a man becomes unmusical from being musical, sick from being
well, and generally in this sense contraries arise from contraries.
Fourthly, as in the 'climax' of Epicharmus; thus from slander comes
railing and from this fighting, and all these are from something in
the sense that it is the efficient cause. In this last class sometimes
the efficient cause is in the things themselves, as in the last
mentioned (for the slander is a part of the whole trouble), and
sometimes external, as the art is external to the work of art or the
torch to the burning house. Now the offspring comes from the semen,
and it is plainly in one of the two following senses that it does
so- either the semen is the material from which it is made, or it is
the first efficient cause. For assuredly it is not in the sense of A
being after B, as the voyage comes from, i.e. after, the
Panathenaea; nor yet as contraries come from contraries, for then
one of the two contraries ceases to be, and a third substance must
exist as an immediate underlying basis from which the new thing
comes into being. We must discover then, in which of the two other
classes the semen is to be put, whether it is to be regarded as
matter, and therefore acted upon by something else, or as a form,
and therefore acting upon something else, or as both at once. For
perhaps at the same time we shall see clearly also how all the
products of semen come into being from contraries, since coming into
being from contraries is also a natural process, for some animals do
so, i.e. from male and female, others from only one parent, as is
the case with plants and all those animals in which male and female
are not separately differentiated. Now that which comes from the
generating parent is called the seminal fluid, being that which
first has in it a principle of generation, in the case of all
animals whose nature it is to unite; semen is that which has in it the
principles from both united parents, as the first mixture which arises
from the union of male and female, be it a foetus or an ovum, for
these already have in them that which comes from both. (Semen, or
seed, and grain differ only in the one being earlier and the other
later, grain in that it comes from something else, i.e. the seed,
and seed in that something else, the grain, comes from it, for both
are really the same thing.)
We must again take up the question what the primary nature of what
is called semen is. Needs must everything which we find in the body
either be (1) one of the natural parts, whether homogeneous or
heterogeneous, or (2) an unnatural part such as a growth, or (3) a
secretion or excretion, or (4) waste-product, or (5) nutriment. (By
secretion or excretion I mean the residue of the nutriment, by
waste-product that which is given off from the tissues by an unnatural
decomposition.)
Now that semen cannot be a part of the body is plain, for it is
homogeneous, and from the homogeneous nothing is composed, e.g. from
only sinew or only flesh; nor is it separated as are all the other
parts. But neither is it contrary to Nature nor a defect, for it
exists in all alike, and the development of the young animal comes
from it. Nutriment, again, is obviously introduced from without.
It remains, then, that it must be either a waste-product or a
secretion or excretion. Now the ancients seem to think that it is a
waste-product, for when they say that it comes from all the body by
reason of the heat of the movement of the body in copulation, they
imply that it is a kind of waste-product. But these are contrary to
Nature, and from such arises nothing according to Nature. So then it
must be a secretion or excretion.
But, to go further into it, every secretion or excretion is either
of useless or useful nutriment; by 'useless' I mean that from which
nothing further is contributed to natural growth, but which is
particularly mischievous to the body if too much of it is consumed; by
'useful' I mean the opposite. Now it is evident that it cannot be of
the former character, for such is most abundant in persons of the
worst condition of body through age or sickness; semen, on the
contrary, is least abundant in them for either they h
ave none at all
or it is not fertile, because a useless and morbid secretion is
mingled with it.
Semen, then, is part of a useful secretion. But the most useful is
the last and that from which finally is formed each of the parts of
the body. For secretions are either earlier or later; of the nutriment
in the first stage the secretion is phlegm and the like, for phlegm
also is a secretion of the useful nutriment, an indication of this
being that if it is mixed with pure nutriment it is nourishing, and
that it is used up in cases of illness. The final secretion is the
smallest in proportion to the quantity of nutriment. But we must
reflect that the daily nutriment by which animals and plants grow is
but small, for if a very little be added continually to the same thing
the size of it will become excessive.
So we must say the opposite of what the ancients said. For whereas
they said that semen is that which comes from all the body, we shall
say it is that whose nature is to go to all of it, and what they
thought a waste-product seems rather to be a secretion. For it is more
reasonable to suppose that the last extract of the nutriment which
goes to all parts resembles that which is left over from it, just as
part of a painter's colour is often left over resembling that which he
has used up. Waste-products, on the contrary, are always due to
corruption or decay and to a departure from Nature.
A further proof that it is not a waste-product, but rather a
secretion, is the fact that the large animals have few young, the
small many. For the large must have more waste and less secretion,
since the great size of the body causes most of the nutriment to be
used up, so that the residue or secretion is small.
Again, no place has been set apart by Nature for waste-products
but they flow wherever they can find an easy passage in the body,
but a place has been set apart for all the natural secretions; thus
the lower intestine serves for the excretion of the solid nutriment,
the bladder for that of the liquid; for the useful part of the
nutriment we have the upper intestine, for the spermatic secretions
the uterus and pudenda and breasts, for it is collected and flows
together into them.
And the resulting phenomena are evidence that semen is what we
have said, and these result because such is the nature of the
secretion. For the exhaustion consequent on the loss of even a very
little of the semen is conspicuous because the body is deprived of the
ultimate gain drawn from the nutriment. With some few persons, it is
true, during a short time in the flower of their youth the loss of it,
if it be excessive in quantity, is an alleviation (just as in the
case of the nutriment in its first stage, if too much have been taken,
since getting rid of this also makes the body more comfortable),
and so it may be also when other secretions come away with it, for
in that case it is not only semen that is lost but also other
influences come away mingled with it, and these are morbid. Wherefore,
with some men at least, that which comes from them proves sometimes
incapable of procreation because the seminal element in it is so
small. But still in most men and as a general rule the result of
intercourse is exhaustion and weakness rather than relief, for the
reason given. Moreover, semen does not exist in them either in
childhood or in old age or in sickness- in the last case because of
weakness, in old age because they do not sufficiently concoct their
food, and in childhood because they are growing and so all the
nutriment is used up too soon, for in about five years, in the case of
human beings at any rate, the body seems to gain half the height
that is gained in all the rest of life.
In many animals and plants we find a difference in this connexion
not only between kinds as compared with kinds, but also between
similar individuals of the same kind as compared with each other, e.g.
man with man or vine with vine. Some have much semen, others little,
others again none at all, not through weakness but the contrary, at
any rate in some cases. This is because the nutriment is used up to
form the body, as with some human beings, who, being in good condition
and developing much flesh or getting rather too fat, produce less
semen and are less desirous of intercourse. Like this is what
happens with those vines which 'play the goat', that is, luxuriate
wantonly through too much nutrition, for he-goats when fat are less
inclined to mount the female; for which reason they thin them before
breeding from them, and say that the vines 'play the goat', so calling
it from the condition of the goats. And fat people, women as well as
men, appear to be less fertile than others from the fact that the
secretion when in process of concoction turns to fat with those who
are too well-nourished. For fat also is a healthy secretion due to
good living.
In some cases no semen is produced at all, as by the willow and
poplar. This condition is due to each of the two causes, weakness
and strength; the former prevents concoction of the nutriment, the
latter causes it to be all consumed, as said above. In like manner
other animals produce much semen through weakness as well as through
strength, when a great quantity of a useless secretion is mixed with
it; this sometimes results in actual disease when a passage is not
found to carry off the impurity, and though some recover of this,
others actually die of it. For corrupt humours collect here as in
the urine, which also has been known to cause disease.
[Further the same passage serves for urine and semen; and whatever
animals have both kinds of excrement, that of liquid and that of solid
nutriment, discharge the semen by the same passage as the liquid
excrement (for it is a secretion of a liquid, since the nutriment
of all animals is rather liquid than solid), but those which have
no liquid excrement discharge it at the passage of the solid
residua. Moreover, waste-products are always morbid, but the removal
of the secretion is useful; now the discharge of the semen
participates in both characteristics because it takes up some of the
non-useful nutriment. But if it were a waste-product it would be
always harmful; as it is, it is not so.]
From what has been said, it is clear that semen is a secretion of
useful nutriment, and that in its last stage, whether it is produced
by all or no.
19
After this we must distinguish of what sort of nutriment it is a
secretion, and must discuss the catamenia which occur in certain of
the vivipara. For thus we shall make it clear (1) whether the female
also produces semen like the male and the foetus is a single mixture
of two semens, or whether no semen is secreted by the female, and, (2)
if not, whether she contributes nothing else either to generation
but only provides a receptacle, or whether she does contribute
something, and, if so, how and in what manner she does so.
We have previously stated that the final nutriment is the blood in
the sanguinea and the analogous fluid in the other animals. Since
the semen is also a secretion of the nutriment, and that in its
final stage, it follows that it will be either (1) blood or that which
is analogous to blood, or (2) something formed from this. But since it
is from the blood, when concocted and somehow divided up, that each
part of the body is made, and since the semen if properly concocted is
quite of a different character from the blood when it is separated
from it, but if not properly concocted has been known in some cases to
issue in a bloody condition if one forces oneself too often to
coition, therefore it is plain that semen will be a secretion of the
nutriment when reduced to blood, being that which is finally
distributed to the parts of the body. And this is the reason why it
has so great power, for the loss of the pure and healthy blood is an
exhausting thing; for this reason also it is natural that the
offspring should resemble the parents, for that which goes to all
the parts of the body resembles that which is left over. So that the
semen which is to form the hand or the face or the whole animal is
already the hand or face or whole animal undifferentiated, and what
each of them is actually such is the semen potentially, either in
virtue of its own mass or because it has a certain power in itself.
I mention these alternatives here because we have not yet made it
clear from the distinctions drawn hitherto whether it is the matter of
the semen that is the cause of generation, or whether it has in it
some faculty and efficient cause thereof, for the hand also or any
other bodily part is not hand or other part in a true sense if it be
without soul or some other power, but is only called by the same
name as the living hand.
On this subject, then, so much may be laid down. But since it is
necessary (1) that the weaker animal also should have a secretion
greater in quantity and less concocted, and (2) that being of such a