Aristotle

by Various Works [lit]

  and 'moulting'. The cause of the condition is deficiency of hot

  moisture, such moisture being especially the unctuous, and hence

  unctuous plants are more evergreen. (However we must elsewhere

  state the cause of this phenomena in plants, for other causes also

  contribute to it.) It is in winter that this happens to plants

  (for the change from summer to winter is more important to them than

  the time of life), and to those animals which hibernate (for

  these, too, are by nature less hot and moist than man); in the latter

  it is the seasons of life that correspond to summer and winter.

  Hence no one goes bald before the time of sexual intercourse, and at

  that time it is in those naturally inclined to such intercourse that

  baldness appears, for the brain is naturally the coldest part of the

  body and sexual intercourse makes men cold, being a loss of pure

  natural heat. Thus we should expect the brain to feel the effect of it

  first, for a little cause turns the scale where the thing concerned is

  weak and in poor condition. Thus if we reckon up these points, that

  the brain itself has but little heat, and further that the skin

  round it must needs have still less, and again that the hair must have

  still less than the skin inasmuch as it is furthest removed from the

  brain, we should reasonably expect baldness to come about this age

  upon those who have much semen. And it is for the same reason that the

  front part of the head alone goes bald in man and that he is the

  only animal to do so; the front part goes bald because the brain is

  there, and man is the only animal to go bald because his brain is much

  the largest and the moistest. Women do not go bald because their

  nature is like that of children, both alike being incapable of

  producing seminal secretion. Eunuchs do not become bald, because

  they change into the female condition. And as to the hair that comes

  later in life, eunuchs either do not grow it at all, or lose it if

  they happen to have it, with the exception of the pubic hair; for

  women also grow that though they have not the other, and this

  mutilation is a change from the male to the female condition.

  The reason why the hair does not grow again in cases of baldness,

  although both hibernating animals recover their feathers or hair and

  trees that have shed their leaves grow leaves again, is this. The

  seasons of the year are the turning-points of their lives, rather than

  their age, so that when these seasons change they change with them

  by growing and losing feathers, hairs, or leaves respectively. But the

  winter and summer, spring and autumn of man are defined by his age, so

  that, since his ages do not return, neither do the conditions caused

  by them return, although the cause of the change of condition is

  similar in man to what it is in the animals and plants in question.

  We have now spoken pretty much of all the other conditions of hair.

  4

  But as to their colour, it is the nature of the skin that is the

  cause of this in other animals and also of their being uni-coloured or

  vari-coloured); but in man it is not the cause, except of the hair

  going grey through disease (not through old age), for in what is

  called leprosy the hairs become white; on the contrary, if the hairs

  are white the whiteness does not invade the skin. The reason is that

  the hairs grow out of skin; if, then, the skin is diseased and white

  the hair becomes diseased with it, and the disease of hair is

  greyness. But the greyness of hair which is due to age results from

  weakness and deficiency of heat. For as the body declines in vigour we

  tend to cold at every time of life, and especially in old age, this

  age being cold and dry. We must remember that the nutriment coming

  to each part of the body is concocted by the heat appropriate to the

  part; if the heat is inadequate the part loses its efficiency, and

  destruction or disease results. (We shall speak more in detail of

  causes in the treatise on growth and nutrition.) Whenever, then,

  the hair in man has naturally little heat and too much moisture enters

  it, its own proper heat is unable to concoct the moisture and so it is

  decayed by the heat in the environing air. All decay is caused by

  heat, not the innate heat but external heat, as has been stated

  elsewhere. And as there is a decay of water, of earth, and all such

  material bodies, so there is also of the earthy vapour, for instance

  what is called mould (for mould is a decay of earthy vapour). Thus

  also the liquid nutriment in the hair decays because it is not

  concocted, and what is called greyness results. It is white because

  mould also, practically alone among decayed things, is white. The

  reason of this is that it has much air in it, all earthy vapour

  being equivalent to thick air. For mould is, as it were, the

  antithesis of hoar-frost; if the ascending vapour be frozen it becomes

  hoar-frost, if it be decayed, mould. Hence both are on the surface

  of things, for vapour is superficial. And so the comic poets make a

  good metaphor in jest when they call grey hairs 'mould of old age' and

  For the one is generically the same as greyness, the other

  specifically; hoar-frost generically (for both are a vapour),

  mould specifically (for both are a form of decay). A proof that this

  is so is this: grey hairs have often grown on men in consequence of

  disease, and later on dark hairs instead of them after restoration

  to health. The reason is that in sickness the whole body is

  deficient in natural heat and so the parts besides, even the very

  small ones, participate in this weakness; and again, much residual

  matter is formed in the body and all its parts in illness, wherefore

  the incapacity in the flesh to concoct the nutriment causes the grey

  hairs. But when men have recovered health and strength again they

  change, becoming as it were young again instead of old; in consequence

  the states change also. Indeed, we may rightly call disease an

  acquired old age, old age a natural disease; at any rate, some

  diseases produce the same effects as old age.

  Men go grey on the temples first, because the back of the head is

  empty of moisture owing to its containing no brain, and the 'bregma'

  has a great deal of moisture, a large quantity not being liable to

  decay; the hair on the temples however has neither so little that it

  can concoct it nor so much that it cannot decay, for this region of

  the head being between the two extremes is exempt from both states.

  The cause of greyness in man has now been stated.

  5

  The reason why this change does not take place visibly on account of

  age in other animals is the same as that already given in the case

  of baldness; their brain is small and less fluid than in man, so

  that the heat required for concoction does not altogether fail.

  Among them it is most clear in horses of all animals that we know,

  because the bone about the brain is thinner in them than in others

  in proportion to their size. A sign of this is that a blow to this

  spot is fatal to them, wherefore Home
r also has said: 'where the first

  hairs grow on the skull of horses, and a wound is most fatal.' As then

  the moisture easily flows to these hairs because of the thinness of

  the bone, whilst the heat fails on account of age, they go grey. The

  reddish hairs go grey sooner than the black, redness also being a sort

  of weakness of hair and all weak things ageing sooner. It is said,

  however, that cranes become darker as they grow old. The reason of

  this would be, if it should prove true, that their feathers are

  naturally moister than others and as they grow old the moisture in the

  feathers is too much to decay easily.

  Greyness comes about by some sort of decay, and is not, as some

  think, a withering. (1) A proof of the former statement is the fact

  that hair protected by hats or other coverings goes grey sooner

  (for the winds prevent decay and the protection keeps off the winds),

  and the fact that it is aided by anointing with a mixture of oil and

  water. For, though water cools things, the oil mingled with it

  prevents the hair from drying quickly, water being easily dried up.

  (2) That the process is not a withering, that the hair does not whiten

  as grass does by withering, is shown by the fact that some hairs

  grow grey from the first, whereas nothing springs up in a withered

  state. Many hairs also whiten at the tip, for there is least heat in

  the extremities and thinnest parts.

  When the hairs of other animals are white, this is caused by nature,

  not by any affection. The cause of the colours in other animals is the

  skin; if they are white, the skin is white, if they are dark it is

  dark, if they are piebald in consequence of a mixture of the hairs, it

  is found to be white in the one part and dark in the other. But in man

  the skin is in no way the cause, for even white-skinned men have

  very dark hair. The reason is that man has the thinnest skin of all

  animals in proportion to his size and therefore it has not strength to

  change the hairs; on the contrary the skin itself changes its colour

  through its weakness and is darkened by sun and wind, while the

  hairs do not change along with it at all. But in the other animals the

  skin, owing to its thickness, has the influence belonging to the

  soil in which a thing grows, therefore the hairs change according to

  the skin but the skin does not change at all in consequence of the

  winds and the sun.

  6

  Of animals some are uni-coloured (I mean by this term those of

  which the kind as a whole has one colour, as all lions are tawny;

  and this condition exists also in birds, fish, and the other classes

  of animals alike); others though many-coloured are yet whole-coloured

  (I mean those whose body as a whole has the same colour, as a bull is

  white as a whole or dark as a whole); others are vari-coloured.

  This last term is used in both ways; sometimes the whole kind is

  vari-coloured, as leopards and peacocks, and some fish, e.g. the

  so-called 'thrattai'; sometimes the kind as a whole is not so, but

  such individuals are found in it, as with cattle and goats and,

  among birds, pigeons; the same applies also to other kinds of birds.

  The whole-coloured change much more than the uniformly coloured,

  both into the simple colour of another individual of the same kind

  (as dark changing into white and vice versa) and into both colours

  mingled. This is because it is a natural characteristic of the kind as

  a whole not to have one colour only, the kind being easily moved in

  both directions so that the colours both change more into one

  another and are more varied. The opposite holds with the uniformly

  coloured; they do not change except by an affection of the colour, and

  that rarely; but still they do so change, for before now white

  individuals have been observed among partridges, ravens, sparrows, and

  bears. This happens when the course of development is perverted, for

  what is small is easily spoilt and easily moved, and what is

  developing is small, the beginning of all such things being on a small

  scale.

  Change is especially found in those animals of which by nature the

  individual is whole-coloured but the kind many-coloured. This is owing

  to the water which they drink, for hot waters make the hair white,

  cold makes it dark, an effect found also in plants. The reason is that

  the hot have more air than water in them, and the air shining

  through causes whiteness, as also in froth. As, then, skins which

  are white by reason of some affection differ from those white by

  nature, so also in the hair the whiteness due to disease or age

  differs from that due to nature in that the cause is different; the

  latter are whitened by the natural heat, the former by the external

  heat. Whiteness is caused in all things by the vaporous air imprisoned

  in them. Hence also in all animals not uniformly coloured all the part

  under the belly is whiter. For practically all white animals are

  both hotter and better flavoured for the same reason; the concoction

  of their nutriment makes them well-flavoured, and heat causes the

  concoction. The same cause holds for those animals which are

  uniformly-coloured, but either dark or white; heat and cold are the

  causes of the nature of the skin and hair, each of the parts having

  its own special heat.

  The tongue also varies in colour in the simply coloured as

  compared with the vari-coloured animals, and again in the simply

  coloured which differ from one another, as white and dark. The

  reason is that assigned before, that the skins of the vari-coloured

  are vari-coloured, and the skins of the white-haired and dark-haired

  are white and dark in each case. Now we must conceive of the tongue as

  one of the external parts, not taking into account the fact that it is

  covered by the mouth but looking on it as we do on the hand or foot;

  thus since the skin of the vari-coloured animals is not uniformly

  coloured, this is the cause of the skin on the tongue being also

  vari-coloured.

  Some birds and some wild quadrupeds change their colour according to

  the seasons of the year. The reason is that, as men change according

  to their age, so the same thing happens to them according to the

  season; for this makes a greater difference to them than the change of

  age.

  The more omnivorous animals are more vari-coloured to speak

  generally, and this is what might be expected; thus bees are more

  uniformly coloured than hornets and wasps. For if the food is

  responsible for the change we should expect varied food to increase

  the variety in the movements which cause the development and so in the

  residual matter of the food, from which come into being hairs and

  feathers and skins.

  So much for colours and hairs.

  7

  As to the voice, it is deep in some animals, high in others, in

  others again well-pitched and in due proportion between both extremes.

  Again, in some it is loud, in others small, and it differs in

  smoothness and roughness, flexibility and inflexibility. We must

  inquire
then into the causes of each of these distinctions.

  We must suppose then that the same cause is responsible for high and

  deep voices as for the change which they undergo in passing from youth

  to age. The voice is higher in all other animals when younger, but

  in cattle that of calves is deeper. We find the same thing also in the

  male and female sexes; in the other kinds of animals the voice of

  the female is higher than that of the male (this being especially

  plain in man, for Nature has given this faculty to him in the

  highest degree because he alone of animals makes use of speech and the

  voice is the material of speech), but in cattle the opposite obtains,

  for the voice of cows is deeper than that of bulls.

  Now the purpose for which animals have a voice, and what is meant by

  'voice' and by 'sound' generally, has been stated partly in the

  treatise on sensation, partly in that on the soul. But since lowness

  of voice depends on the movement of the air being slow and its

  highness on its being quick, there is a difficulty in knowing

  whether it is that which moves or that which is moved that is the

  cause of the slowness or quickness. For some say that what is much

  is moved slowly, what is little quickly, and that the quantity of

  the air is the cause of some animals having a deep and others a high

  voice. Up to a certain point this is well said (for it seems to be

  rightly said in a general way that the depth depends on a certain

  amount of the air put in motion), but not altogether, for if this

  were true it would not be easy to speak both soft and deep at once,

  nor again both loud and high. Again, the depth seems to belong to

  the nobler nature, and in songs the deep note is better than the

  high-pitched ones, the better lying in superiority, and depth of

  tone being a sort of superiority. But then depth and height in the

  voice are different from loudness and softness, and some high-voiced

  animals are loud-voiced, and in like manner some soft-voiced ones

  are deep-voiced, and the same applies to the tones lying between these

  extremes. And by what else can we define these (I mean loudness and