It will have been observed that, so far, the merit of originating atomism has been attributed to Leucippus, instead of to the more celebrated Democritus, with whose name it is usually associated. The two were fast friends, and seem always to have worked together in perfect harmony. But Leucippus, although next to nothing is known of his life, was apparently the older man, and from him, so far as we can make out, emanated the great idea, which his brilliant coadjutor carried into every department of enquiry, and set forth in works which are a loss to literature as well as to science, for the poetic splendour of their style was not less remarkable than the encyclopaedic range of their contents. Democritus was born at Abdêra, a Thracian city, 470 B.C., a year before Socrates, and lived to a very advanced age—more than a hundred, according to some accounts. However this may be, he was probably, like most of his great countrymen, possessed of immense vitality. His early manhood was spent in Eastern travel, and he was not a little proud of the numerous countries which he had visited, and the learned men with whom he had conversed. His time was mostly occupied in observing Nature, and in studying mathematics; the sages of Asia and Egypt may have acquainted him with many useful scientific facts, but we have seen that his philosophy was derived from purely Hellenic sources. A few fragments of his numerous writings still survive—the relics of an intellectual Ozymandias. In them are briefly shadowed forth the conceptions which Lucretius, or at least his modern English interpreters, have made familiar to all educated men and women. Everything is the result of mechanical causation. Infinite worlds are formed by the collision of infinite atoms falling for ever downward through infinite space. No place is left for supernatural agency; nor are the unaided operations of Nature disguised under Olympian appellations. Democritus goes even further than Epicurus in his rejection of the popular mythology. His system provides no interstellar refuge for abdicated gods. He attributed a kind of objective existence to the apparitions seen in sleep, and even a considerable influence for good or for evil, but denied that they were immortal. The old belief in a Divine Power had arisen from their activity and from meteorological phenomena of an alarming kind, but was destitute of any stronger foundation. For his own part, he looked on the fiery spherical atoms as a universal reason or soul of the world, without, however, assigning to them the distinct and commanding position occupied by a somewhat analogous principle in the system which we now proceed to examine, and with which our survey of early Greek thought will most fitly terminate.
V.
Reasons have already been suggested for placing Anaxagoras last in order among the physical philosophers, notwithstanding his priority in point of age to more than one of them. He was born, according to the most credible accounts, 500 B.C., at Clazomenae, an Ionian city, and settled in Athens when twenty years of age. There he spent much the greater part of a long life, illustrating the type of character which Euripides—expressly referring, as is supposed, to the Ionian sage—has described in the following choric lines:
‘Happy is he who has learned
To search out the secret of things,
Not to the townsmen’s bane,
Neither for aught that brings
An unrighteous gain.
But the ageless order he sees
Of nature that cannot die,
And the causes whence it springs,
And the how and the why.
Never have thoughts like these
To a deed of dishonour been turned.’28
The dishonour was for the townsmen who, in an outbreak of insane fanaticism, drove the blameless truthseeker from his adopted home. Anaxagoras was the intimate companion of Pericles, and Pericles had made many enemies by his domestic as well as by his foreign policy. A coalition of harassed interests and offended prejudices was formed against him. A cry arose that religion and the constitution were in danger. The Athenians had too much good sense to dismiss their great democratic Minister, but they permitted the illustrious statesman’s political opponents to strike at him through his friends.29 Aspasia was saved only by the tears of her lover. Pheidias, the grandest, most spiritual-minded artist of all time, was arrested on a charge of impiety, and died in a prison of the city whose temples were adorned with the imperishable monuments of his religious inspiration. A decree against ‘astronomers and atheists’ was so evidently aimed at Anaxagoras that the philosopher retired to Lampsacus, where he died at the age of seventy-two, universally admired and revered. Altars dedicated to Reason and Truth were erected in his honour, and for centuries his memory continued to be celebrated by an annual feast.30 His whole existence had been devoted to science. When asked what made life worth living, he answered, ‘The contemplation of the heavens and of the universal cosmic order.’ The reply was like a title-page to his works. We can see that specialisation was beginning, that the positive sciences were separating themselves from general theories about Nature, and could be cultivated independently of them. A single individual might, indeed, combine philosophy of the most comprehensive kind with a detailed enquiry into some particular order of phenomena, but he could do this without bringing the two studies into any immediate connexion with each other. Such seems to have been the case with Anaxagoras. He was a professional astronomer and also the author of a modified atomic hypothesis. This, from its greater complexity, seems more likely to have been suggested by the purely quantitative conception of Leucippus than to have preceded it in the order of evolution. Democritus, and probably his teacher also, drew a very sharp distinction between what were afterwards called the primary and secondary qualities of matter. Extension and resistance alone had a real existence in Nature, while the attributes corresponding to our special sensations, such as temperature, taste, and colour, were only subjectively, or, as he expressed it, conventionally true. Anaxagoras affirmed no less strongly than his younger contemporaries that the sum of being can neither be increased nor diminished, that all things arise and perish by combination and division, and that bodies are formed out of indestructible elements; like the Atomists, again, he regarded these elementary substances as infinite in number and inconceivably minute; only he considered them as qualitatively distinct, and as resembling on an infinitesimal scale the highest compounds that they build up. Not only were gold, iron, and the other metals formed of homogeneous particles, but such substances as flesh, bone, and blood were, according to him, equally simple, equally decomposable, into molecules of like nature with themselves. Thus, as Aristotle well observes, he reversed the method of Empedocles, and taught that earth, air, fire, and water were really the most complex of all bodies, since they supplied nourishment to the living tissues, and therefore must contain within themselves the multitudinous variety of units by whose aggregation individualised organic substance is made up.31 Furthermore, our philosopher held that originally this intermixture had been still more thoroughgoing, all possible qualities being simultaneously present in the smallest particles of matter. The resulting state of chaotic confusion lasted until Nous, or Reason, came and segregated the heterogeneous elements by a process of continuous differentiation leading up to the present arrangement of things. Both Plato and Aristotle have commended Anaxagoras for introducing into speculation the conception of Reason as a cosmic world-ordering power; both have censured him for making so little use of his own great thought, for attributing almost everything to secondary, material, mechanical causes; for not everywhere