CHAPTER XVII.. The Epicurean Views on Nature.

THE EPICUREAN VIEWS ON NATURE.

If Epicurus and his followers underrated logic, to natural science they attached a considerable value. This value was, however, exclusively derived from a sense of the practical advantages which a knowledge of nature confers in opposing superstition. Without such an object the study of nature would have seemed wholly superfluous. Such being their attitude of mind, the Epicureans were, as might have been expected, indifferent about giving a complete and accurate explanation of phenomena. Their one aim was to put forward such a view of nature as would do away with the necessity for supernatural intervention, without at the same time pretending to offer a sufficient solution of the problems raised by science. Whilst, therefore, he devoted considerable attention to natural science, Epicurus does not seem to have considered certainty to be of importance, or even to be possible, in dealing with details of scientific study. Of the general causes of things we can and ought to entertain a firm conviction, since the possibility of overcoming religious prejudices and the fears occasioned by them depends on these convictions. No such result, however, follows from the investigation of details, which, on the contrary, only tends to confirm prejudices in those who are not already emancipated from them. In dealing with details, therefore, it is enough for Epicurus to show that various natural causes for phenomena may be imagined, and to offer various suggestions which dispense with the intervention of the Gods and the myths of a belief in Providence. To say that any one of these suggestions is the only possible one, is in most cases to exceed the bounds of experience and human knowledge, and to go back to the capricious explanations of mythology. Possibly the world may move, and possibly it may be at rest. Possibly it may be round, or else it may be triangular, or have any other shape. Possibly the sun and the stars may be extinguished at setting, and be lighted afresh at rising. It is, however, equally possible that they may only disappear under the earth and reappear again, or that their rising and setting may be due to yet other causes. Possibly the waxing and waning of the moon may be caused by the moon’s revolving; or it may be due to an atmospheric change, or to an actual increase and decrease in the moon’s size, or to some other cause. Possibly the moon may shine with borrowed light, or it may shine with its own, experience supplying us with instances of bodies which give their own light, and of those which have their light borrowed. From these and such-like statements it appears that questions of natural science in themselves have no value for Epicurus. Whilst granting that only one natural explanation of phenomena is generally possible, yet in any particular case he is perfectly indifferent which explanation is adopted.

Great stress is, however, laid by him on the general explanation. In contrast with the religious view which regards the world as a system of means leading to ends, the leading business of the natural science of the Epicureans is to refer all phenomena to natural causes. To an Epicurean nothing appeals more absurd than to suppose that the arrangements of nature have for their object the well-being of mankind, or that they have any object at all. The tongue is not given us for the purpose of speaking, nor the ears for the purpose of hearing. As a matter of fact, it would, indeed, be more correct to say, that we speak because we have a tongue, and hear because we have ears. Natural powers have acted purely according to the law of necessity, and among their various products there could not fail to be some presenting the appearance of purpose in their arrangement. In the case of man there have resulted many such products and powers. But this result is by no means intentional; it is an accidental consequence of natural causes. In explaining nature all thought of Gods must be put out of sight. For their happiness would be inconceivable, on the supposition that they cared for man and his welfare.

Confining his interest in nature, as Epicurus did, entirely to this general view of things, he was all the more inclined, in carrying it into details, to rely upon some older system. No system, however, appeared to correspond better with his tone of mind than that of Democritus, which, moreover, commended itself to him not only by absolutely banishing the idea of final cause, but by referring everything to matter, and by its theory of atoms. As Epicurus places in each individual thing taken by itself the ultimate end of action, so Democritus had theoretically made all that is real to consist in what is absolutely individual or in atoms. His natural science, therefore, seemed to present the most natural basis for the Epicurean Ethics. If the Stoics, in their views of nature, closely followed Heraclitus, Epicurus in his followed Democritus still more closely, and hence, with the exception of one single point, the additions made by Epicurus to the theory of this philosopher are of no philosophical importance.

With Democritus Epicurus agreed in holding that there is no other form of reality except that of bodily reality. Every substance, he says in the words of the Stoics, must affect others, and be affected by them; and whatever affects others or is itself affected, is corporeal. Corporeal substance is, therefore, the only kind of substance. The various qualities of things, essential as well as accidental qualities, are accordingly not incorporeal existences, but simply chance modes of body, the former being called by Epicurus συμβεβηκότα, the latter συμπτώματα. But a second something is necessary besides corporeal substance in order to explain phenomena, viz. empty space. That empty space exists is proved by the differences of weight in bodies. For what else could be the cause of this difference? It is proved still more conclusively by motion, motion being impossible without empty space. Mind as a moving cause, however, seems to Epicurus altogether superfluous. Everything that exists consists of bodies and empty space, and there is no third thing.

Democritus had resolved the two conceptions of body and empty space into the conceptions of being and not being. True to his position, Epicurus dispensed with this speculative basis, and clinging to the ordinary notions of empty space, and of a material filling space, he simply proves these notions by the qualities of phenomena. For this very reason Democritus’s division of body into innumerable primary particles or atoms appeared to him most necessary. All bodies known to us by sensation are composed of parts. If the process of division were infinitely continued, all things would ultimately be resolved into the non-existent—in this Epicurus and Democritus agree;—and conversely all things must have been formed out of the non-existent, in defiance of the first principle of natural science that nothing can come from nothing, and that nothing can be resolved into nothing. Hence, we must conclude that the primary component parts of things can neither have come into existence nor cease to exist, nor yet be changed in their nature. These primary bodies contain no empty space in themselves, and hence can neither be divided nor destroyed, nor be changed in any way. They are so small that they do not impress the senses, and as a matter of fact we do not see them. Nevertheless they must not be regarded as mathematical atoms, the name atoms being assigned to them only because their bodily structure will not admit of division. They have neither colour, warmth, smell, nor any other property; properties belong only to distinct materials; and for this reason they must not be sought in the four elements, all of which, as experience shows, come into being and pass away. They possess only the universal qualities of all corporeal things, viz. shape, size, and weight.

Not only must atoms, like all other bodies, have shape, but there must exist among them indefinitely many varieties of shape, or it would be impossible to account for the innumerable differences of things. There cannot, however, be really an infinite number of shapes, as Democritus maintained, in any limited body—this is intelligible of itself—nor yet in the whole universe, since an unlimited number would make the arrangement of the world impossible, everything in the world being circumscribed by certain containing limits. Again, atoms must be different in point of size; for all materials cannot be divided into particles of equal size. Yet even to this difference there must be some limitation. An atom must neither be so large as to become an object of sense, nor can it, after what has been said, be infinitely small. From difference in point of size the difference of atoms in point of weight follows. In point of number atoms must be innumerable, and in the same way empty space must be unbounded also. For since everything bounded must be bounded by something, it is impossible to imagine any bounds of the universe beyond which nothing exists, and hence there can be no bounds at all. The absence of bounds must, apply to the mass of atoms quite as much as to empty space. If an infinite number of atoms would not find room in a limited space, conversely a limited number of atoms would be lost in empty space, and never able to form a world. In all these views Epicurus closely follows Democritus, no doubt agreeing with him also in explaining the qualities of things by the composition of their atoms.

In deducing the origin of things from their primary causes, Epicurus, however, deviates widely from his predecessor. Atoms—so it was taught by both—have by virtue of their weight been eternally engaged in a downward motion. That all bodies should move downwards in empty space seemed to Epicurus a matter of course; for whatever is heavy must fall unless it is supported. He was therefore opposed to the Aristotelian view that heaviness shows itself in the form of attraction towards a centre, and consequently to his further supposition that downward mode of motion belongs only to certain bodies, circular motion being for others more natural. The objection that in endless space there is no above or below he could meet only by appealing to experience; some things always appear above our heads, others beneath our feet. But whilst Democritus held that atoms in their downward motion meet together, thus giving rise to a rotatory motion, no such view commended itself to Epicurus. Nay rather in his view all atoms will fall equally fast, since empty space offers no resistance, and falling perpendicularly it is impossible to see how they can meet. To render a meeting possible he supposes the smallest possible swerving aside from the perpendicular line in falling. This assumption seemed to him indispensable, since it would be otherwise impossible to assert the freedom of the human will. For how can the will be free if everything falls according to the strict law of gravity? For the same reason this swerving aside was not supposed to proceed from any natural necessity, but simply from the power of self-motion in the atoms. In consequence of their meeting one part of the atoms rebounds—so Democritus also taught; the lighter ones are forced upwards, and from the upward and downward motions combined a rotatory motion arises. When this motion takes place a clustering of atoms is the consequence, which by their own motion separate themselves from the remaining mass, and form a world of themselves. Atoms being eternal and unchangeable, the process of forming worlds must go on without beginning or end; and inasmuch as they are also infinite in number, and empty space is infinite also, there must be an innumerable number of worlds. In the character of these worlds the greatest possible variety may be supposed, since it is most unlikely that the innumerable combinations of atoms all brought about at random will fall out alike. Equally impossible is it to assert that all these worlds are absolutely dissimilar. In general, Epicurus assumed that they are extremely different both in point of size and arrangement, and that here and there one may be similar to our own. Moreover, since eternity affords time for all imaginable combinations of atoms, nothing can ever be brought about now which has not already existed. In one respect all worlds are alike; they come into existence, are liable to decay, and, like all other individual elements, are exposed to a gradual increase and decrease. So we might have assumed from other positions in his system. Between the individual worlds both Democritus and Epicurus insert intermediate world-spaces, in which by the clustering of atoms from time to time new worlds come into being.

The origin of our world is thus described. At a certain period of time—Lucretius believes at no very distant period—a cluster of atoms of varying shape and size was formed in this definite portion of space. These atoms meeting, there first arose from the pressure and rebound of the quickly falling particles motions of every variety in every direction. Soon the greater atoms pressing downwards, by dint of weight forced upwards the smaller and lighter atoms, the fiery ones topmost and with the greatest impetus to form the ether, and afterwards those which form the air. The upper pressure ceasing, these masses, under the pressure of particles still joining it from below, spread forth sidewards, and thus the belts of fire and air were formed. Next uprose those atoms out of which the sun and stars are formed into the heights, and at the same time the earth settled down, its inner part being partially exhausted in those places where the sea now is. By the influence of the warmth of the ether, and the sun-heat, the earth-mass was bound together more closely, the sea was pressed out of it, and the surface assumed an uneven character. The world is shut off from other worlds and from empty space by those bodies which form its external boundary.

Asking, in the next place, what idea must be formed of the arrangement of the world, we are met by the two principles which Epicurus is never weary of inculcating; one, that we must explain nothing as an intentional arrangement by deity, but refer everything simply and solely to mechanical causes; the other, that in explaining phenomena the widest possible room must be given for hypotheses of every kind, and that nothing is more absurd than to abridge the wide range of possible explanations by exclusively deciding in favour of any one. Thereby the investigation of nature loses for him its value as such, nor is it of any great interest to us to follow his speculations on nature into detail. On one point he dogmatises, protesting that the framework of heaven must not be considered the work of God, nor must life and reason be attributed to the stars. Otherwise, on nearly all the questions which engaged the attention of astronomers at that time, he observes the greatest indifference, treating the views of his predecessors, good and bad alike, with an easy superficiality which can only be explained by supposing him altogether indifferent as to their truth. The state of his own astronomical knowledge can, moreover, be easily seen by recalling the notorious assertion that the sun, the moon, and the stars are either not at all, or only a little larger, and may possibly be even less than they appear to be. The Epicureans also thought to support their theory that the earth, borne by the air, reposes in the middle of the world—a theory which on their hypothesis of the weight of bodies is impossible —by the gradual diminution in weight of the surrounding bodies. It would be impossible here to go through the treatment which they gave to atmospheric and terrestrial phenomena, particularly as the principle already indicated was most freely used, and many explanations were given as being all equally possible.

Out of the newly made earth plants at first grew, and afterwards animals came forth, since the latter, according to Lucretius, can by no possibility have fallen from heaven. In other worlds, likewise, living beings came into existence, though not necessarily in all. Among these beings were originally, as Empedocles had previously supposed, all sorts of composite or deformed creatures. Those, however, alone continued to exist which were fitted by nature to find support, to propagate, and to protect themselves from danger. Romantic creatures, such as centaurs of chimæras, can never have existed here, because the beings of which they are compounded would require conditions of life altogether different.

Aiming, as the Epicureans did, at explaining the origin of men and animals in a purely natural manner, they likewise tried to form an idea, equally according to nature, of the original state and historical development of the human race. In this attempt they ignored all legendary notions, and, notwithstanding their leaning towards materialism, they on the whole advocated perfectly sound views. The men of early times, so thought Lucretius, were stronger and more powerful than the men of to-day. Rude and ignorant as beasts, they lived in the woods in a perpetual state of warfare with the wild animals, without justice or society. The first and most important step in a social direction was the discovery of fire, the learning to build huts, and to clothe themselves in skins; then began marriage and domestic life, and speech, originally not a matter of convention, but, like the noises of animals, the natural expression of thoughts and feelings, was developed. The older the human race grew, the more they learned of the arts and skill which minister to the preservation and enjoyment of life. These arts were first learnt by experience, under the pressure of nature, or the compulsion of want. What had thus been discovered was completed by reflection, the more gifted preceding the rest as teachers. In exactly the same way civil society was developed. Individuals built strongholds, and made themselves rulers. In time the power of kings aroused envy, and they were massacred. To crush the anarchy which then arose, magistrates were chosen, and order established by penal laws. It will subsequently be seen that Epicurus explained religion in the same way by natural growth.

The apotheosis of nature, which has been apparent in Epicurus’s whole view of history, becomes specially prominent in his treatment of psychology. This treatment could, after all that has been said, be only purely materialistic. The soul, like every other real being, is a body. In support of this view the Epicureans appealed to the mutual relations of the body and the soul, agreeing on this point with the Stoics. The body of the soul, however, consists of the finest, lightest, and most easily moved atoms, as is manifest from the speed of thought, from the instantaneous dissolution of the soul after death, and, moreover, from the fact that the soulless body is as heavy as the body in which there is a soul. Hence Epicurus, again agreeing with the Stoics, describes the soul as a material resembling fire and air, or, more accurately, as composed of four elements, fire, air, vapour, and a fourth nameless element. It consists of the finest atoms, and is the cause of feeling, and according as one or other of these elements preponderates, the character of man is of one or the other kind. Like the Stoics, Epicurus believed that the soul-element is received by generation from the parents’ souls, and that it is spread over the whole body, growing as the body grows. At the same time he makes a distinction somewhat similar to that made by the Stoics in their doctrine of the sovereign part of the soul (ἡγεμονικόν). Only the irrational part of the soul is diffused as a principle of life over the whole body; the rational part has its seat in the breast. To the rational part belong mental activity, sensation, and perception, the motion of the will and the mind, and in this latter sense life itself; both parts together make up one being, yet they may exist in different conditions. The mind may be cheerful whilst the body and the irrational soul feel pain, or the reverse may be the case. It is even possible that portions of the irrational soul may be lost by the mutilation of the body, without detriment to the rational soul, or consequently to life. When, however, the connection between soul and body is fully severed, then the soul can no longer exist. Deprived of the surrounding shelter of the body, its atoms are dispersed in a moment, owing to their lightness; and the body in consequence, being unable to exist without the soul, goes over into corruption. If this view appears to hold out the most gloomy prospect for the future, Epicurus considers that it cannot really be so. With life every feeling of evil ceases, and the time when we shall no longer exist affects us just as little as the time before we existed. Nay, more, he entertains the opinion that his teaching alone can reconcile us to death by removing all fear of the nether world and its terrors.

Allowing that many of these statements are natural consequences of the principles of Epicurus, the distinction between a rational and an irrational soul must, nevertheless, at first sight seem strange in a system so thoroughly materialistic as was that of the Epicureans. And yet this distinction is not stranger than the corresponding parts of the Stoic teaching. If the Stoic views may be referred to the distinction which they drew in morals between the senses and the reason, not less are the Epicurean ethics marked by the same contrast between the general and the sensuous side of the mind. Hence Epicurus shares the Stoic belief in an ethereal origin of the human race; and although this belief as at first expressed only implies that man, like other living beings, is composed of ethereal elements, yet there is connected with it the distinction already discussed in the case of the Stoics between the higher and the lower parts of man, which ultimately comes to be simply another mode of expressing the difference between mind and matter.

Among the phenomena of the soul’s life sensation is made to harmonise with the general principles of the Epicurean view of nature by the aid of Democritus’s doctrine of atom-pictures (εἴδωλα). From the surface of bodies—this is the pith of that doctrine—the finest possible particles are constantly being thrown off, which by virtue of their fineness traverse the furthest spaces in an infinitely short time, hurrying through the void. Many of these exhalations are arrested by some obstacle soon after coming forth, or are otherwise thrown into confusion. In the case of others the atoms for a long time retain the same position and connection which they had in bodies themselves, thus presenting a picture of things, and only lacking corporeal solidity. As these pictures are conveyed to the soul by the various organs of sense, our impressions of things arise. Even those impressions, which have no corresponding real object, must be referred to such pictures present in the soul. For often pictures last longer than things themselves; and often by a casual combination of atoms pictures are formed in the air resembling no one single thing. Sometimes, too, pictures of various kinds are combined on their way to the senses; thus, for instance, the notion of a Centaur is caused by the union of the picture of a man with that of a horse, not only in our imagination, but already previously in the atom-picture. If, therefore, sensation distorts or imperfectly represents real objects, it must be explained as being due to some change or mutilation in the atom-pictures before they reach our senses.

In thus explaining mental impressions, the Epicureans do not allow themselves to be disturbed by the fact that we can recall at pleasure the ideas of all possible things. The cause of this power was rather supposed to be the circumstance that we are always surrounded by an innumerable number of atom-pictures, none of which we perceive unless our attention is directed to them. Likewise the seeming motion of forms which we behold in dreams is explained by the hasty succession of similar atom-pictures, appearing to us as changes of one and the same picture. But besides receiving pictures supplied from without, spontaneous motion with regard to these pictures takes place on our part, a motion connected in the first instance with the soul’s motion when it receives the outward impression, but not to be regarded as a simple continuation thereof. This independent motion gives rise to opinion, and hence opinion is not so necessary or so universally true as feeling. It may agree with feeling, or it may not agree with it. It may be true or it may be false. The conditions of its being true or false have been previously investigated.

Impressions also give rise to will and action, the soul being set in motion by impressions, and this motion extending from the soul to the body. Into the nature of will, however, Epicurus does not appear to have instituted a more careful psychological investigation. It was enough for him to assert the freedom of the will. This freedom he considers absolutely indispensable, if anything we do is to be considered our own, unless we are prepared to despair of moral responsibility altogether, and to resign ourselves to a comfortless and inexorable necessity. To make freedom possible, Epicurus had introduced accident into the motion of atoms, and for the same reason he denies the truth of disjunctive propositions which apply to the future. In the latter respect, he, no doubt, only attacked the material truth of two clauses, without impugning the formal accuracy of the disjunction, i.e. he did not deny that of two contradictory cases either one or the other must happen, nor did he deny the truth of saying: To-morrow Epicurus will either be alive or not alive. But he disputed the truth of each clause taken by itself. He denied the truth of the sentence, Epicurus will be alive; and equally that of its contradictory, Epicurus will not be alive; on the ground that the one or the other statement only becomes true by the actual realisation of an event at present uncertain. For this he deserves little blame. Our real charge against him is that he did not more thoroughly investigate the nature of the will and the conception of freedom, and that he treats the subject of the soul as scantily and superficially as he had treated the subject of nature.