We have now to study an analogous, though far less complicated, antagonism in ancient Greece, and to show how her most brilliant period of physical philosophy arose from the combination of two seemingly irreconcilable systems. Parmenides, in an address supposed to be delivered by Wisdom to her disciple, warns us against the method pursued by ‘ignorant mortals, the blind, deaf, stupid, confused tribes, who hold that to be and not to be are the same, and that all things move round by an inverted path.’[19] What Parmenides denounced as arrant nonsense was deliberately proclaimed to be the highest truth by his illustrious contemporary, Heracleitus, of Ephesus. This wonderful thinker is popularly known as the weeping philosopher, because, according to a very silly tradition, he never went abroad without shedding tears over the follies of mankind. No such mawkish sentimentality, but bitter scorn and indignation, marked the attitude of Heracleitus towards his fellows. A self-taught sage, he had no respect for the accredited instructors of Hellas. ‘Much learning,’ he says, ‘does not teach reason, else it would have taught Hesiod and Pythagoras, Xenophanes and Hecataeus.’[20] Homer, he declares, ought to be flogged out of the public assemblages, and Archilochus likewise. When the highest reputations met with so little mercy, it will readily be imagined what contempt he poured on the vulgar herd. The feelings of a high-born aristocrat combine with those of a lofty genius to point and wing his words. ‘The many are bad and few are the good. The best choose one thing instead of all, a perpetual well-spring of fame, while the many glut their appetites like beasts. One man is equal to ten thousand if he is the best.’ This contempt was still further intensified by the very excusable incapacity of the public to understand profound thought conveyed in a style proverbial for its obscurity. ‘Men cannot comprehend the eternal law; when I have explained the order of Nature they are no wiser than before.’ What, then, was this eternal law, a knowledge of which Heracleitus found so difficult to popularise? Let us look back for a moment at the earlier Ionian systems. They had taught that the universe arose either by differentiation or by condensation and expansion from a single primordial substance, into which, as Anaximander, at least, held, everything, at last returned. Now, Heracleitus taught that this transformation is a universal, never-ending, never-resting process; that all things are moving; that Nature is like a stream in which no man can bathe twice; that rest and stability are the law, not of life, but of death. Again, the Pythagorean school, as we have seen, divided all things into a series of sharply distinguished antithetical pairs. Heracleitus either directly identified the terms of every opposition, or regarded them as necessarily combined, or as continually passing into one another. Perhaps we shall express his meaning most thoroughly by saying that he would have looked on all three propositions as equivalent statements of a single fact. In accordance with this principle he calls war the father and king and lord of all, and denounces Homer’s prayer for the abolition of strife as an unconscious blasphemy against the universe itself. Yet, even his powerful intellect could not grasp the conception of a shifting relativity as the law and life of things without embodying it in a particular material substratum. Following the Ionian tradition, he sought for a world-element, and found it in that cosmic fire which enveloped the terrestrial atmosphere, and of which the heavenly luminaries were supposed to be formed. ‘Fire,’ says the Ephesian philosopher, no doubt adapting his language to the comprehension of a great commercial community, ‘is the general medium of exchange, as gold is given for everything, and everything for gold.’ ‘The world was not created by any god or any man, but always was, and is, and shall be, an ever-living fire, periodically kindled and quenched.‘ By cooling and condensation, water is formed from fire, and earth from water; then, by a converse process called the way up as the other was the way down, earth again passes into water and water into fire. At the end of certain stated periods the whole world is to be reconverted into fire, but only to enter on a new cycle in the series of its endless revolutions—a conception, so far, remarkably confirmed by modern science. The whole theory, including a future world conflagration, was afterwards adopted by the Stoics, and probably exercised a considerable influence on the eschatology of the early Christian Church. Imagination is obliged to work under forms which thought has already superseded; and Heracleitus as a philosopher had forestalled the dazzling consummation to which as a prophet he might look forward in wonder and hope. For, his elemental fire was only a picturesque presentation indispensable to him, but not to us, of the sovereign law wherein all things live and move and have their being. To have introduced such an idea into speculation was his distinctive and inestimable achievement, although it may have been suggested by the εἱμαρμένη or destiny of the theological poets, a term occasionally employed in his writings. It had a moral as well as a physical meaning, or rather it hovers ambiguously between the two. ‘The sun shall not transgress his bounds, or the Erinyes who help justice will find him out.’ It is the source of human laws, the common reason which binds men together, therefore they should hold by it even more firmly than by the laws of the State. It is not only all-wise but all-good, even where it seems to be the reverse; for our distinctions between good and evil, just and unjust, vanish in the divine harmony of Nature, the concurrent energies and identifying transformations of her universal life.

According to Aristotle, the Heracleitean flux was inconsistent with the highest law of thought, and made all predication impossible. It has been shown that the master himself recognised a fixed recurring order of change which could be affirmed if nothing else could. But the principle of change, once admitted, seemed to act like a corrosive solvent, too powerful for any vessel to contain. Disciples were soon found who pushed it to extreme consequences with the effect of abolishing all certainty whatever. In Plato’s time it was impossible to argue with a Heracleitean; he could never be tied down to a definite statement. Every proposition became false as soon as it was uttered, or rather before it was out of the speaker’s mouth. At last, a distinguished teacher of the school declined to commit himself by using words, and disputed exclusively in dumb show. A dangerous speculative crisis had set in. At either extremity of the Hellenic world the path of scientific inquiry was barred; on the one hand by a theory eliminating non-existence from thought, and on the other hand by a theory identifying it with existence. The luminous beam of reflection had been polarised into two divergent rays, each light where the other was dark and dark where the other was light, each denying what the other asserted and asserting what the other denied. For a century physical speculation had taught that the universe was formed by the modification of a single eternal substance, whatever that substance might be. By the end of that period, all becoming was absorbed into being at Elea, and all being into becoming at Ephesus. Each view contained a portion of the truth, and one which perhaps would never have been clearly perceived if it had not been brought into exclusive prominence. But further progress was impossible until the two half-truths had been recombined. We may compare Parmenides and Heracleitus to two lofty and precipitous peaks on either side of an Alpine pass. Each commands a wide prospect, interrupted only on the side of its opposite neighbour. And the fertilising stream of European thought originates with neither of them singly, but has its source midway between.

IV.

We now enter on the last period of purely objective philosophy, an age of mediating and reconciling, but still profoundly original speculation. Its principal representatives, with whom alone we have to deal, are Empedocles, the Atomists, Leucippus and Democritus, and Anaxagoras. There is considerable doubt and difficulty respecting the order in which they should be placed. Anaxagoras was unquestionably the oldest and Democritus the youngest of the four, the difference between their ages being forty years. It is also nearly certain that the Atomists came after Empedocles. But if we take a celebrated expression of Aristotle’s[21] literally (as there is no reason why it should not be taken), Anaxagoras, although born before Empedocles, published his views at a later period. Was he also anticipated by Leucippus? We cannot tell with certainty, but it seems likely from a comparison of their doctrines that he was; and in all cases the man who naturalised philosophy in Athens, and who by his theory of a creative reason furnishes a transition to the age of subjective speculation, will be most conveniently placed at the close of the pre-Socratic period.

A splendid tribute has been paid to the fame of Empedocles by Lucretius, the greatest didactic poet of all time, and by a great didactic poet of our own time, Mr. Matthew Arnold. But the still more rapturous panegyric pronounced by the Roman enthusiast on Epicurus makes his testimony a little suspicious, and the lofty chant of our own contemporary must be taken rather as an expression of his own youthful opinions respecting man’s place in Nature, than as a faithful exposition of the Sicilian thinker’s creed. Many another name from the history of philosophy might with better reason have been prefixed to that confession of resigned and scornful scepticism entitled Empedocles on Etna. The real doctrines of an essentially religious teacher would hardly have been so cordially endorsed by Mr. Swinburne. But perhaps no other character could have excited the deep sympathy felt by one poetic genius for another, when with both of them thought is habitually steeped in emotion. Empedocles was the last Greek of any note who threw his philosophy into a metrical form. Neither Xenophanes nor Parmenides had done this with so much success. No less a critic than Aristotle extols the Homeric splendour of his verses, and Lucretius, in this respect an authority, speaks of them as almost divine. But, judging from the fragments still extant, their speculative content exhibits a distinct decline from the height reached by his immediate predecessors. Empedocles betrays a distrust in man’s power of discovering truth, almost, although not quite, unknown to them. Too much certainty would be impious. He calls on the ‘much-wooed white-armed virgin muse’ to—

‘Guide from the seat of Reverence thy bright car,

And bring to us the creatures of a day,

What without sin we may aspire to know.’[22]

We also miss in him their single-minded devotion to philosophy and their rigorous unity of doctrine. The Acragantine sage was a party leader (in which capacity, to his great credit, he victoriously upheld the popular cause), a rhetorician, an engineer, a physician, and a thaumaturgist. The well-known legend relating to his death may be taken as a not undeserved satire on the colossal self-conceit of the man who claimed divine honours during his lifetime. Half-mystic and half-rationalist, he made no attempt to reconcile the two inconsistent sides of his intellectual character. It may be compared to one of those grotesque combinations in which, according to his morphology, the heads and bodies of widely different animals were united during the beginnings of life before they had learned to fall into their proper places. He believed in metempsychosis, and professed to remember the somewhat miscellaneous series of forms through which his own personality had already run. He had been a boy, a girl, a bush, a bird, and a fish. Nevertheless, as we shall presently see, his theory of Nature altogether excluded such a notion as the soul’s separate existence. We have now to consider what that theory actually was. It will be remembered that Parmenides had affirmed the perpetuity and eternal self-identity of being, but that he had deprived this profound divination of all practical value by interpreting it in a sense which excluded diversity and change. Empedocles also declares creation and destruction to be impossible, but explains that the appearances so denominated arise from the union and separation of four everlasting substances—earth, air, fire, and water. This is the famous doctrine of the four elements, which, adopted by Plato and Aristotle, was long regarded as the last word of chemistry, and still survives in popular phraseology. Its author may have been guided by an unconscious reflection on the character of his own philosophical method, for was not he, too, constructing a new system out of the elements supplied by his predecessors? They had successively fixed on water, air, and fire as the primordial form of existence; he added a fourth, earth, and effected a sort of reconciliation by placing them all on an equal footing. Curiously enough, the earlier monistic system had a relative justification which his crude eclecticism lacked. All matter may exist either in a solid, a liquid, or a gaseous form; and all solid matter has reached its present condition after passing through the two other degrees of consistency. That the three modifications should be found coexisting in our own experience is a mere accident of the present régime, and to enumerate them is to substitute a description for an explanation, the usual fault of eclectic systems. Empedocles, however, besides his happy improvement on Parmenides, made a real contribution to thought when, as Aristotle puts it, he sought for a moving as well as for a material cause; in other words, when he asked not only of what elements the world is composed, but also by what forces were they brought together. He tells us of two such causes, Love and Strife, the one a combining, the other a dissociating power. If for these half-mythological names we read attractive and repulsive forces, the result will not be very different from our own current cosmologies. Such terms, when so used as to assume the existence of occult qualities in matter, driving its parts asunder or drawing them close together, are, in truth, as completely mythological as any figments of Hellenic fancy. Unlike their modern antitypes, the Empedoclean goddesses did not reign together, but succeeded one another in alternate dominion during protracted periods of time. The victory of Love was complete when all things had been drawn into a perfect sphere, evidently the absolute Eleatic Being subjected to a Heracleitean law of vicissitude and contradiction. For Strife lays hold on the consolidated orb, and by her disintegrating action gradually reduces it to a formless chaos, till, at the close of another world-period, the work of creation begins again. Yet growth and decay are so inextricably intertwined that Empedocles failed to keep up this ideal separation, and was compelled to admit the simultaneous activity of both powers in our everyday experience, so that Nature turns out to be composed of six elements instead of four, the mind which perceives it being constituted in a precisely similar manner. But Love, although on the whole victorious, can only gradually get the better of her retreating enemy, and Nature, as we know it, is the result of their continued conflict. Empedocles described the process of evolution, as he conceived it, in somewhat minute detail. Two points only are of much interest to us, his alleged anticipation of the Darwinian theory and his psychology. The former, such as it was, has occasionally been attributed to Lucretius, but the Roman poet most probably copied Epicurus, although the very brief summary of that philosopher’s physical system preserved by Diogenes Laertius contains no allusion to such a topic. We know, however, that in Aristotle’s time a theory identical with that of Lucretius was held by those who rejected teleological explanations of the world in general and of living organisms in particular. All sorts of animals were produced by spontaneous generation; only those survived which were accidentally furnished with appliances for procuring nourishment and for propagating their kind. The notion itself originated with Empedocles, whose fanciful suppositions have already been mentioned in a different connexion. Most assuredly he did not offer it as a solution of problems which in his time had not yet been mooted, but as an illustration of the confusion which prevailed when Love had only advanced a little way in her ordering, harmonising, unifying task. Prantl, writing a few years before the appearance of Mr. Darwin’s book on the Origin of Species, and therefore without any prejudice on the subject, observes with truth that this theory of Empedocles was deeply rooted in the mythological conceptions of the time.[23] Perhaps he was seeking for a rationalistic explanation of the centaurs, minotaurs, hundred-handed giants, and so forth, in whose existence he had not, like Lucretius, learned completely to disbelieve. His strange supposition was afterwards freed from its worst extravagances; but even as stated in the De Rerum Naturâ, it has no claim whatever to rank as a serious hypothesis. Anything more unlike the Darwinian doctrine, according to which all existing species have been evolved from less highly-organized ancestors by the gradual accumulation of minute differences, it would be difficult to conceive. Every thinker of antiquity, with one exception, believed in the immutability of natural species. They had existed unchanged from all eternity, or had sprung up by spontaneous generation from the earth’s bosom in their present form. The solitary dissentient was Anaximander, who conjectured that man was descended from an aquatic animal.[24] Strange to say, this lucky guess has not yet been quoted as an argument against the Ascidian pedigree. It is chiefly the enemies of Darwinism who are eager to find it anticipated in Empedocles or Lucretius. By a curious inversion of traditionalism, it is fancied that a modern discovery can be upset by showing that somebody said something of the kind more than two thousand years ago. Unfortunately authority has not the negative value of disproving the principles which it supports. We must be content to accept the truths brought to light by observation and reasoning, even at the risk of finding ourselves in humiliating agreement with a philosopher of antiquity.[25]

Passing from life to mind, we find Empedocles teaching an even more pronounced materialism than Parmenides, inasmuch as it is stated in language of superior precision. Our souls are, according to him, made up of elements like those which constitute the external world, each of these being perceived by a corresponding portion of the same substances within ourselves—fire by fire, water by water, and so on with the rest. It is a mistake to suppose that speculation begins from a subjective standpoint, that men start with a clear consciousness of their own personality, and proceed to construct an objective universe after the same pattern. Doubtless they are too prone to personify the blind forces of Nature, and Empedocles himself has just supplied us with an example of this tendency, but they err still more by reading outward experience into their own souls, by materialising the processes of consciousness, and resolving human personality into a loose confederacy of inorganic units. Even Plato, who did more than anyone else towards distinguishing between mind and body, ended by laying down his psychology on the lines of an astronomical system. Meanwhile, to have separated the perception of an object from the object itself, in ever so slight a degree, was an important gain to thought. We must not omit to notice a hypothesis by which Empedocles sought to elucidate the mechanism of sensation, and which was subsequently adopted by the atomic school; indeed, as will presently be shown, we have reason to believe that the whole atomic theory was developed out of it. He held that emanations were being continually thrown off from the surfaces of bodies, and that they penetrated into the organs of sense through fine passages or pores. This may seem a crude guess, but it is at any rate much more scientific than Aristotle’s explanation. According to the latter, possibilities of feeling are converted into actualities by the presence of an object. In other words, we feel when and because we do; a safe assertion, but hardly an addition to our positive knowledge of the subject.