Contemporary with the work of Aristotle and his insistence upon the necessity that each individual man should seek for the chief good in the sphere of his own actual experience, occurred the relaxation of the dominant claims of the State to the best part of the energies and activities of the citizen. The change in the political condition of Greece consequent upon the Macedonian conquest had turned the Greek citizen back upon his own soul for inspiration to guide his steps aright. The philosophical tendency was thus aided by external conditions, and the joint operation of both these influences established in Stoicism and Epicureanism the satisfaction of the moral requirements of the individual man as the aim and end of Philosophy. Whatever importance the leaders of the Stoics attached to Logic and Physics—and different philosophers formed different estimates of their value[87]—all were agreed that these parts of Philosophy were only useful in so far as they enabled mankind to lead a virtuous life; a life in harmony with nature and its laws; a life which placed them above the domination of “_Fear and hope and phantasy and awe, And wistful yearning and unsated loves, That strain beyond the limits of this life_.”[88] The Epicureans repudiated Dialectic,[89] and, as already stated, studied Physics with a view only to freeing the mind of man from those supernatural fears which hampered him in his attainment of terrestrial virtue and happiness:— “Nam veluti pueri trepidant atque omnia cæcis In tenebris metuunt, sic nos in luce timemus Interdum nilo quæ sunt metuenda magis quam Quæ pueri in tenebris pavitant finguntque futura. Hunc igitur terrorem animi tenebrasque necesse est Non radii solis neque lucida tela diei Discutiant, sed naturæ species ratioque.” Lucretius, whose great poem is devoted to an exposition of the physical side of Epicureanism, _i.e._ of the Atomic Philosophy of Democritus,[90] is only on the same ground with Epicurus himself when he makes it clear, not merely by the general complexion of his argument, but by a large number of particular passages, and those, too, the most strikingly beautiful in the poem, that the investigation of natural phenomena is to serve only as a means of freeing the life of humanity from those cares and vices which are hostile to its peace:— “Denique avarities et honorum cæca cupido Quæ miseros homines cogunt transcendere fines Juris et interdum socios scelerum atque ministros Noctes atque dies niti præstante labore Ad summas emergere opes, hæc vulnera vitæ Non minimam partem _mortis formidine_ aluntur.”