by Aristotle
than the more general and wider characteristics. Coriscus is both a
man and an animal, but his manhood is nearer to his individual
existence than is his animalhood. In generation both the individual
and the class are operative, but the individual is the more so of
the two, for this is the only true existence. And the offspring is
produced indeed of a certain quality, but also as an individual, and
this latter is the true existence. Therefore it is from the forces
of all such existences that the efficient movements come which exist
in the semen; potentially from remoter ancestors but in a higher
degree and more nearly from the individual (and by the individual I
mean e.g. Coriscus or Socrates). Now since everything changes not
into anything haphazard but into its opposite, therefore also that
which is not prevailed over in generation must change and become the
opposite, in respect of that particular force in which the paternal
and efficient or moving element has not prevailed. If then it has
not prevailed in so far as it is male, the offspring becomes female;
if in so far as it is Coriscus or Socrates, the offspring does not
resemble the father but the mother. For as 'father' and 'mother' are
opposed as general terms, so also the individual father is opposed
to the individual mother. The like applies also to the forces that
come next in order, for the offspring always changes rather into the
likeness of the nearer ancestor than the more remote, both in the
paternal and in the maternal line.
Some of the movements exist in the semen actually, others
potentially; actually, those of the father and the general type, as
man and animal; potentially those of the female and the remoter
ancestors. Thus the male and efficient principle, if it lose its own
nature, changes to its opposites, but the movements which form the
embryo change into those nearly connected with them; for instance,
if the movement of the male parent be resolved, it changes by a very
slight difference into that of his father, and in the next instance
into that of his grandfather; and in this way not only in the male but
also in the female line the movement of the female parent changes into
that of her mother, and, if not into this, then into that of her
grandmother; and similarly also with the more remote ancestors.
Naturally then it is most likely that the characteristics of
'male' and of the individual father will go together, whether they
prevail or are prevailed over. For the difference between them is
small so that there is no difficulty in both concurring, for
Socrates is an individual man with certain characters. Hence for the
most part the male offspring resemble the father, and the female the
mother. For in the latter case the loss of both characters takes place
at once, and the change is into the two opposites; now is opposed to
male, and the individual mother to the individual father.
But if the movement coming from the male principle prevails while
that coming from the individual Socrates does not, or vice versa, then
the result is that male children are produced resembling the mother
and female children resembling the father.
If again the movements be resolved, if the male character remain but
the movement coming from the individual Socrates be resolved into that
of the father of Socrates, the result will be a male child
resembling its grandfather or some other of its more remote
ancestors in the male line on the same principle. If the male
principle be prevailed over, the child will be female and resembling
most probably its mother, but, if the movement coming from the
mother also be resolved, it will resemble its mother's mother or the
resemblance will be to some other of its more remote ancestors in
the female line on the same principle.
The same applies also to the separate parts, for often some of these
take after the father, and others after the mother, and yet others
after some of the remoter ancestors. For, as has been often said
already, some of the movements which form the parts exist in the semen
actually and others potentially. We must grasp certain fundamental
general principles, not only that just mentioned (that some of the
movements exist potentially and others actually), but also two
others, that if a character be prevailed over it changes into its
opposite, and, if it be resolved, is resolved into the movement next
allied to it- if less, into that which is near, if more, into that
which is further removed. Finally, the movements are so confused
together that there is no resemblance to any of the family or kindred,
but the only character that remains is that common to the race, i.e.
it is a human being. The reason of this is that this is closely knit
up with the individual characteristics; 'human being' is the general
term, while Socrates, the father, and the mother, whoever she may
be, are individuals.
The reason why the movements are resolved is this. The agent is
itself acted upon by that on which it acts; thus that which cuts is
blunted by that which is cut by it, that which heats is cooled by that
which is heated by it, and in general the moving or efficient cause
(except in the case of the first cause of all) does itself receive
some motion in return; e.g. what pushes is itself in a way pushed
again and what crushes is itself crushed again. Sometimes it is
altogether more acted upon than is the thing on which it acts, so that
what is heating or cooling something else is itself cooled or
heated; sometimes having produced no effect, sometimes less than it
has itself received. (This question has been treated in the special
discussion of action and reaction, where it is laid down in what
classes of things action and reaction exist.) Now that which is acted
on escapes and is not mastered by the semen, either through deficiency
of power in the concocting and moving agent or because what should
be concocted and formed into distinct parts is too cold and in too
great quantity. Thus the moving agent, mastering it in one part but
not in another, makes the embryo in formation to be multiform, as
happens with athletes because they eat so much. For owing to the
quantity of their food their nature is not able to master it all, so
as to increase and arrange their form symmetrically; therefore their
limbs develop irregularly, sometimes indeed almost so much that no one
of them resembles what it was before. Similar to this is also the
disease known as satyrism, in which the face appears like that of a
satyr owing to a quantity of unconcocted humour or wind being diverted
into parts of the face.
We have thus discussed the cause of all these phenomena, (1)
female and male offspring are produced, (2) why some are similar to
their parents, female to female and male to male, and others the other
way about, females being similar to the father and males to the
mother, and in general why some are like their ancestors while
others are like none of them, and all this
as concerns both the body
as a whole and each of the parts separately. Different accounts,
however, have been given of these phenomena by some of the
nature-philosophers; I mean why children are like or unlike their
parents. They give two versions of the reason. Some say that the child
is more like that parent of the two from whom comes more semen, this
applying equally both to the body as a whole and to the separate
parts, on the assumption that semen comes from each part of both
parents; if an equal part comes from each, then, they say, the child
is like neither. But if this is false, if semen does not come off from
the whole body of the parents, it is clear that the reason assigned
cannot be the cause of likeness and unlikeness. Moreover, they are
hard put to it to explain how it is that a female child can be like
the father and a male like the mother. For (1) those who assign the
same cause of sex as Empedocles or Democritus say what is on other
grounds impossible, and (2) those who say that it is determined by the
greater or smaller amount of semen coming the male or female parent,
and that this is why one child is male and another female, cannot show
how the female is to resemble the father and the male the mother,
for it is impossible that more should come from both at once. Again,
for what reason is a child generally like its ancestors, even the more
remote? None of the semen has come from them at any rate.
But those who account for the similarity in the manner which remains
to be discussed, explain this point better, as well as the others. For
there are some who say that the semen, though one, is as it were a
common mixture (panspermia) of many elements; just as, if one should
mix many juices in one liquid and then take some from it, it would
be possible to take, not an equal quantity always from each juice, but
sometimes more of one and sometimes more of another, sometimes some of
one and none at all of another, so they say it is with the
generative fluid, which is a mixture of many elements, for the
offspring resembles that parent from which it has derived most. Though
this theory is obscure and in many ways fictitious, it aims at what is
better expressed by saying that what is called 'panspermia' exists
potentially, not actually; it cannot exist actually, but it can do
so potentially. Also, if we assign only one sort of cause, it is not
easy to explain all the phenomena, (1) the distinction of sex, (2) why
the female is often like the father and the male like the mother,
and again (3) the resemblance to remoter ancestors, and further (4)
the reason why the offspring is sometimes unlike any of these but
still a human being, but sometimes, (5) proceeding further on these
lines, appears finally to be not even a human being but only some kind
of animal, what is called a monstrosity.
For, following what has been said, it remains to give the reason for
such monsters. If the movements imparted by the semen are resolved and
the material contributed by the mother is not controlled by them, at
last there remains the most general substratum, that is to say the
animal. Then people say that the child has the head of a ram or a
bull, and so on with other animals, as that a calf has the head of a
child or a sheep that of an ox. All these monsters result from the
causes stated above, but they are none of the things they are said
to be; there is only some similarity, such as may arise even where
there is no defect of growth. Hence often jesters compare some one who
is not beautiful to a 'goat breathing fire', or again to a 'ram
butting', and a certain physiognomist reduced all faces to those of
two or three animals, and his arguments often prevailed on people.
That, however, it is impossible for such a monstrosity to come
into existence- I mean one animal in another- is shown by the great
difference in the period of gestation between man, sheep, dog, and ox,
it being impossible for each to be developed except in its proper
time.
This is the description of some of the monsters talked about; others
are such because certain parts of their form are multiplied so that
they are born with many feet or many heads.
The account of the cause of monstrosities is very close and
similar in a way to that of the cause of animals being born
defective in any part, for monstrosity is also a kind of deficiency.
4
Democritus said that monstrosities arose because two emissions of
seminal fluid met together, the one succeeding the other at an
interval of time; that the later entering into the uterus reinforced
the earlier so that the parts of the embryo grow together and get
confused with one another. But in birds, he says, since copulation
takes place quickly, both the eggs and their colour always cross one
another. But if it is the fact, as it manifestly is, that several
young are produced from one emission of semen and a single act of
intercourse, it is better not to desert the short road to go a long
way about, for in such cases it is absolutely necessary that this
should occur when the semen is not separated but all enters the female
at once.
If, then, we must attribute the cause to the semen of the male, this
will be the way we shall have to state it, but we must rather by all
means suppose that the cause lies in the material contributed by the
female and in the embryo as it is forming. Hence also such
monstrosities appear very rarely in animals producing only one young
one, more frequently in those producing many, most of all in birds and
among birds in the common fowl. For this bird produces many young, not
only because it lays often like the pigeon family, but also because it
has many embryos at once and copulates all the year round. Therefore
it produces many double eggs, for the embryos grow together because
they are near one another, as often happens with many fruits. In
such double eggs, when the yolks are separated by the membrane, two
separate chickens are produced with nothing abnormal about them;
when the yolks are continuous, with no division between them, the
chickens produced are monstrous, having one body and head but four
legs and four wings; this is because the upper parts are formed
earlier from the white, their nourishment being drawn from the yolk,
whereas the lower part comes into being later and its nourishment is
one and indivisible.
A snake has also been observed with two heads for the same reason,
this class also being oviparous and producing many young.
Monstrosities, however, are rarer among them owing to the shape of the
uterus, for by reason of its length the numerous eggs are set in a
line.
Nothing of the kind occurs with bees and wasps, because their
brood is in separate cells. But in the fowl the opposite is the
case, whereby it is plain that we must hold the cause of such
phenomena to lie in the material. So, too, monstrosities are
commoner in other animals if they produce many young. Hence they are
less common in man, for he produces for the most part only one young
one and that perfect; even in man monstrosities occur more often in
regions where the women give birth to more than one at a time, as in
Egypt. And they are commoner in sheep and goats, since they produce
more young. Still more does this apply to the fissipeds, for such
animals produce many young and imperfect, as the dog, the young of
these creatures being generally blind. Why this happens and why they
produce many young must be stated later, but in them Nature has made
an advance towards the production of monstrosities in that what they
generate, being imperfect, is so far unlike the parent; now
monstrosities also belong to the class of things unlike the parent.
Therefore this accident also often invades animals of such a nature.
So, too, it is in these that the so-called 'metachoera' are most
frequent, and the condition of these also is in a way monstrous, since
both deficiency and excess are monstrous. For the monstrosity
belongs to the class of things contrary to Nature, not any and every
kind of Nature, but Nature in her usual operations; nothing can happen
contrary to Nature considered as eternal and necessary, but we speak
of things being contrary to her in those cases where things
generally happen in a certain way but may also happen in another
way. In fact, even in the case of monstrosities, whenever things occur
contrary indeed to the established order but still always in a certain
way and not at random, the result seems to be less of a monstrosity
because even that which is contrary to Nature is in a certain sense
according to Nature, whenever, that is, the formal nature has not
mastered the material nature. Therefore they do not call such things
monstrosities any more than in the other cases where a phenomenon
occurs habitually, as in fruits; for instance, there is a vine which
some call 'capneos'; if this bear black grapes they do not judge it
a monstrosity because it is in the habit of doing this very often. The
reason is that it is in its nature intermediate between white and