Aristotle

by Various Works [lit]

  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