In the Roman republic and empire, a general scepticism had likewise arisen among the philosophers as the first fruit of intellectual development, and the educated classes were speedily divided between avowed or virtual atheists, like the Epicureans,(155) and pure theists, like the Stoics and the Platonists. The first, represented by such writers as Lucretius and Petronius, regarded the gods simply as the creations of fear, denied every form of Providence, attributed the world to a concurrence of atoms, and life to spontaneous generation, and regarded it as the chief end of philosophy to banish as illusions of the imagination every form of religious belief. The others formed a more or less pantheistic conception of the Deity, asserted the existence of a Providence,(156) but treated with great contempt the prevailing legends which they endeavoured in various ways to explain. The first systematic theory of explanation appears to have been that of the Sicilian Euhemerus, whose work was translated by Ennius. He pretended that the gods were originally kings, whose history and genealogies he professed to trace, and who after death had been deified by mankind.(157) Another attempt, which in the first period of Roman scepticism was more generally popular, was that of some of the Stoics, who regarded the gods as personifications of the different attributes of the Deity, or of different forces of nature. Thus Neptune was the sea, Pluto was fire, Hercules represented the strength of God, Minerva His wisdom, Ceres His fertilising energy.(158) More than a hundred years before the Empire, Varro had declared that “the soul of the world is God, and that its parts are true divinities.”(159) Virgil and Manilius described, in lines of singular beauty, that universal spirit, the principle of all life, the efficient cause of all motion, which permeates and animates the globe. Pliny said that “the world and sky, in whose embrace all things are enclosed, must be deemed a god, eternal, immense, never begotten, and never to perish. To seek things beyond this is of no profit to man, and they transcend the limits of his faculties.”(160) Cicero had adopted the higher Platonic conception of the Deity as mind freed from all taint of matter,(161) while Seneca celebrated in magnificent language “Jupiter the guardian and ruler of the universe, the soul and spirit, the lord and master of this mundane sphere, ... the cause of causes, upon whom all things hang.... Whose wisdom oversees the world that it may move uncontrolled in its course, ... from whom all things proceed, by whose spirit we live, ... who comprises all we see.”(162) Lucan, the great poet of stoicism, rose to a still higher strain, and to one which still more accurately expressed the sentiments of his school, when he described Jupiter as that majestic, all-pervasive spirit, whose throne is virtue and the universe.(163) Quintilian defended the subjugation of the world beneath the sceptre of a single man, on the