by Aristotle
Indeed, it is not unreasonable that some of the images which come before the mind in sleep may even be causes of the actions cognate to each of them. For as when we are about to act, or are engaged in any course of action, or have already performed certain actions, we often find ourselves concerned with these actions, or performing them, in a vivid dream; and the cause of this is that the dream-movement [25] has had a way paved for it from the original movements set up in the daytime; exactly so, but conversely, it must often happen that the movements set up first in sleep should also prove to be starting-points of actions to be performed in the daytime, since the recurrence by day of the thought of these actions also has had its way paved for it in the images before the mind at night. Thus then it is quite [30] conceivable that some dreams may be signs and causes.
Most dreams are, however, to be classed as mere coincidences, especially all such as are extravagant, and those in the fulfilment of which the dreamers have no [463b1] initiative, such as in the case of a sea-fight, or of things taking place far away. As regards these it is natural that the fact should stand as it does whenever a person, on mentioning something, finds the very thing mentioned come to pass. Why, indeed, should this not happen also in sleep? The probability is, rather, that many such [5] things should happen. As, then, one’s remembering a particular person is neither sign nor cause of this person’s presenting himself, so, in the parallel instance, the dream is, to him who has seen it, neither sign nor cause of its fulfilment, but a mere coincidence. Hence the fact that many dreams have no fulfilment, for coincidences [10] do not occur according to any universal or general law.
2 · On the whole, forasmuch as certain of the other animals also dream, it may be concluded that dreams are not sent by God, nor are they designed for this purpose. They have a mysterious aspect, however, for nature is mysterious, though not divine. A sign is this: the power of foreseeing the future and of having vivid [15] dreams is found in persons of inferior type, which implies that God does not send their dreams; but merely that all those whose physical temperament is, as it were, garrulous and melancholic, see sights of all descriptions; for, inasmuch as they experience many movements of every kind, they just chance to have visions resembling objective facts, their luck in these matters being merely like that of persons who play at dice. For the principle which is expressed in the gambler’s [20] maxim: ‘If you make many throws your luck must change,’ holds good in their case also.
That many dreams have no fulfilment is not strange, for it is so too with many bodily symptoms and weather-signs, e.g., those of rain or wind. For if another [25] movement occurs more influential than that from which, while the event still future, the given sign was derived, the event does not take place. So, of the things which ought to be accomplished by human agency, many, though well-planned, are by the operation of other principles more powerful brought to nought. For, speaking generally, that which was going to happen is not in every case what now is happening; nor is that which will in fact happen identical with that which is going to [30] happen. Still, however, we must hold that the beginnings from which, as we said, no consummation follows, are indeed beginnings, and these constitute natural signs of certain events, even though the events do not come to pass.
[464a1] As for dreams which involve not such beginnings as we have here described, but such as are extravagant in times, or places, or magnitudes; or those involving beginnings which are not extravagant in any of these respects, while yet the persons who see the dream do not have matters in their own hands: unless the foresight which such dreams give is the result of pure coincidence, the following would be a [5] better explanation of it than that proposed by Democritus, who alleges phantoms and emanations as its cause. As, when something has caused motion in water or air, this moves another and, though the cause has ceased to operate, such motion propagates itself to a certain point, though there the prime mover is not present; just so it may well be that a movement and a consequent sense-perception should reach [10] sleeping souls from the objects from which Democritus represents emanations as coming; that such movements, in whatever way they arrive, should be more perceptible at night, because when proceeding thus in the daytime they are more liable to dissolution (since at night the air is less disturbed, there being then less [15] wind); and that they shall be perceived within the body owing to sleep, since persons are more sensitive even to slight internal movements when asleep than when awake. It is these movements then that cause images, as a result of which sleepers foresee the future even relatively to such events as those referred to above. These [20] considerations also explain why this experience befalls people at random and not the most intelligent. For it would have regularly occurred both in the daytime and to the wise had it been God who sent it; but, as we have explained the matter, it is quite natural that random persons should be those who have foresight. For the mind of such persons is not given to thinking, but, as it were, derelict, or totally vacant, and, when once set moving, is borne passively on in the direction taken by that which [25] moves it. With regard to the fact that some persons who are liable to derangement have this foresight, its explanation is that their normal mental movements do not impede the alien movements, but are beaten off by them. That is why they have an especially keen perception of the alien movements.
That certain persons in particular should have vivid dreams, e.g. that familiar friends should thus have foresight in a special degree respecting one another, is due to the fact that such friends are most solicitous on one another’s behalf. For as [30] acquaintances are quick to recognize and perceive one another a long way off, so also they do as regards the sensory movements respecting one another; for sensory movements which refer to persons familiarly known are themselves more familiar. Atrabilious persons, owing to their impetuosity, are, when they, as it were, shoot from a distance, expert at hitting; while, owing to their mutability, the series of movements deploys quickly before their minds. For as even the insane recite the [464b1] poems of Philaenis, so what they say and think is connected by mere similarity— e.g. ‘Aphrodite, phrodite’—and thus they go on stringing things together. Moreover, owing to their impetuosity, one movement within them is not liable to be knocked out of its course by some other movement. [5]
The most skilful interpreter of dreams is he who has the faculty of observing resemblances. Any one may interpret dreams which are vivid and plain. But, speaking of resemblances, I mean that dream images are analogous to the forms reflected in water, as indeed we have already stated. In the latter case, if the motion [10] in the water be great, the reflexion has no resemblance to its original, nor do the forms resemble the real objects. Skilful, indeed, would he be in interpreting such reflexions who could rapidly discern, and at a glance comprehend, the scattered and distorted fragments of such forms, so as to perceive that one of them represents a man, or a horse, or anything whatever—similarly, then, in the case of seeing what [15] this dream means; for the internal movement effaces the clearness of the dream.
The questions, therefore, which we proposed as to the nature of sleep and the dream, and the cause to which each of them is due, and also as to divination as a result of dreams, in every form of it, have now been discussed.
**TEXT: W. D. Ross, Aristotle: Parva Naturalia, Clarendon Press, Oxford, 1955
ON LENGTH AND SHORTNESS OF LIFE**
G. R. T. Ross
[20] 1 · The reasons for some animals being long-lived and others short-lived, and, in a word, the causes of the length and brevity of life call for investigation.
The necessary beginning to our inquiry is a statement of the difficulties about these points. For it is not clear whether in animals and plants universally it is a single or diverse cause that makes some to be long-lived, others short-lived. Plants [25] too have in some cases a long life, while in others it lasts but for a year.
Further, in a natural structure are longevity and a sound constitution coincident, or is shortness of life independent of unhealthiness? P
erhaps in the case of certain maladies a diseased state of the body and shortness of life are [30] interchangeable, while in the case of others ill-health is perfectly compatible with long life.
Of sleep and waking we have already treated; about life and death we shall speak later on, and likewise about health and disease, in so far as it belongs to the [465a1] science of nature to do so. But at present we have to investigate the causes of some creatures being long-lived, others short-lived as we have said before. We find this distinction affecting not only entire genera opposed as wholes to one another, but applying also to contrasted sets of individuals within the same species. As an [5] instance of the difference applying to the genus I give man and horse (for mankind has a longer life than the horse), while within the species there is the difference between man and man; for of men also some are long-lived, others short-lived, differing from each other in respect of the different regions in which they dwell. Races inhabiting warm countries have longer life, those living in a cold climate live [10] a shorter time. Likewise there are similar differences among individuals occupying the same locality.
2 · We must answer the question, What is that which, in natural objects, makes them easily destroyed, or the reverse? Since fire and water, and whatsoever [15] is akin thereto, do not possess identical powers they are reciprocal causes of generation and decay. Hence it is natural to infer that everything else arising from them and composed of them should share in the same nature, in all cases where things are not, like a house, a composite unity formed by the synthesis of many things.
In other matters a different account must be given; for in many things their mode of dissolution is something peculiar to themselves, e.g. in knowledge and [20] ignorance, health and disease. These pass away even though the medium in which they are found is not destroyed but continues to exist; for example, take the termination of ignorance, which is recollection or learning, while knowledge passes away into forgetfulness, or error. But accidentally the disintegration of a natural object is accompanied by the destruction of the other things; for, when the animal dies, the health or knowledge resident in it passes away too. Hence from these [25] considerations we may draw a conclusion about the soul too; for, if the inherence of soul in body is not a matter of nature but like that of knowledge in the soul, there would be another mode of dissolution pertaining to it besides that which occurs when the body is destroyed. But since evidently it does not admit of this dual [30] dissolution, the soul must stand in a different case in respect of its union with the body.
3 · Perhaps one might reasonably raise the question whether there is any [465b1] place where what is corruptible becomes incorruptible, as fire does in the upper regions where it meets with no opposite. Opposites destroy each other, and hence accidentally, by their destruction, whatsoever is attributed to them is destroyed. But no opposite in a real substance is accidentally destroyed, because real substance is [5] not predicated of any subject. Hence a thing which has no opposite, or which is situated where it has no opposite, cannot be destroyed. For what will that be which can destroy it, if destruction comes only through contraries, but no contrary to it exists either absolutely or in the particular place where it is? But perhaps this is in [10] one sense true, in another sense not true, for it is impossible that anything containing matter should not have in any sense an opposite. Heat and straightness can be present in every part of a thing, but it is impossible that the thing should be nothing but hot or white or straight; for, if that were so, attributes would have a separate existence. Hence if, in all cases, whenever the active and the passive exist [15] together, the one acts and the other is acted on, it is impossible that no change should occur. Further, this is so if a waste product is an opposite, and waste must always be produced; for opposition is always the source of change, and waste is what remains of the previous opposite. But, after expelling everything of a nature actually opposed, an object would in this case also be imperishable. Or would it be [20] destroyed by the environment?
If then that is so, what we have said sufficiently accounts for the change; but, if not, we must assume that something of actually opposite character is in the changing object, and waste is produced.
Hence accidentally a lesser flame is consumed by a greater one, for the nutriment, to wit the smoke, which the former takes a long period to expend, is used [25] up by the big flame quickly.1
Hence all things are at all times in a state of transition and are coming into being or passing away. The environment acts on them either favourably or antagonistically, and, owing to this, things that change their situation become more or less enduring than their nature warrants, but never are they eternal when they [30] contain contrary qualities; for their matter is an immediate source of contrariety, so that if it involves locality they show change of situation, if quantity, increase and diminution, while if it involves qualitative affection we find alteration of character.
[466a1] 4 · We find that a superior immunity from decay attaches neither to the largest animals (the horse has shorter life than man) nor to those that are small (for many insects live but for a year). Nor are plants as a whole less liable to perish than animals (many plants are annuals), nor have sanguineous animals the pre-eminence [5] (for the bee is longer-lived than certain sanguineous animals). Neither is it the bloodless animals that live longest (for molluscs live only a year, though bloodless), nor terrestrial organisms (there are both plants and terrestrial animals of which a single year is the period), nor the occupants of the sea (for there we find the crustaceans and the molluscs, which are short-lived).
Speaking generally, the longest-lived things occur among the plants, e.g. the [10] date-palm. Next in order we find them among the sanguineous animals rather than among the bloodless, and among land animals rather than among water animals. Hence, taking these two characters together, the longest-lived animals fall among sanguineous land animals, e.g. man and elephant. As a matter of fact also it is a [15] general rule that the larger live longer than the smaller, for the other long-lived animals too happen to be of a large size, as are also those I have mentioned.
5 · The following considerations may enable us to understand the reasons for all these facts. We must remember that an animal is by nature humid and warm, and to live is to be of such a constitution, while old age is dry and cold, and so is a [20] corpse. This is plain to observation. But the material constituting the bodies of all animals consists of the following—the hot and the cold, the dry and the moist. Hence when they age they must become dry, and therefore the fluid in them requires to be not easily dried up. Thus we explain why fat things are not liable to decay. The reason is that they contain air; now air relatively to the other elements is fire, and fire never becomes rotten.
[25] Again the humid element in animals must not be small in quantity, for a small quantity is easily dried up. This is why both plants and animals that are large are, as a general rule, longer-lived than the rest, as was said before; it is to be expected that the larger should contain more moisture. But it is not merely this that makes them longer lived; for the cause is twofold, to wit, the quality as well as the quantity of the [30] fluid. Hence the moisture must be not only great in amount but also warm, in order to be neither easily congealed nor easily dried up.
It is for this reason also that man lives longer than some animals which are larger; for animals live longer though there is a deficiency in the amount of their moisture, if the ratio of its qualitative [466b1] superiority exceeds that of its quantitative deficiency.
In some creatures the warm element is their fatty substance, which prevents at once desiccation and cooling; but in others it assumes a different flavour. Further, that which is designed to be not easily destroyed should not yield waste products. [5] Anything of such a nature causes death either by disease or naturally, for the potency of the waste product works adversely and destroys now the entire constitution, now a particular member.
This is why animals that copulate frequently and tho
se abounding in seed age quickly; the seed is a residue, and further, by being lost, it produces dryness. Hence the mule lives longer than either the horse or the ass from which it sprang, and [10] females live longer than males if the males copulate frequently. Accordingly cock-sparrows have a shorter life than the females. Again males subject to great toil are short-lived and age more quickly owing to the labour; toil produces dryness and old age is dry. But by natural constitution and as a general rule males live longer [15] than females, and the reason is that the male is an animal with more warmth than the female.
The same kind of animals are longer-lived in warm than in cold climates for the same reason as they are of larger size. The size of animals of cold constitution illustrates this particularly well, and hence snakes and lizards and scaly reptiles are [20] of great size in warm localities, as also are testacea in the Red Sea: the warm humidity there is the cause equally of their augmented size and of their life. But in cold countries the humidity in animals is more of a watery nature, and hence is readily congealed. Consequently it happens that animals with little or no blood are [25] in northerly regions either entirely absent (both land and water animals) or, when they do occur, they are smaller and have shorter life; for the frost prevents growth.