In Philosophy the Romans originated nothing. Their energies in the earlier years of the state were wholly absorbed in organization and conquest. Resting in a stern and simple creed, they had little speculative interest in matters outside the hard routine of their daily life. But with the close of the Period of Conquest came a change. The influx of wealth from conquered provinces, the formation of large landed estates, the excessive employment of slave labor, and the consequent rise of a new aristocracy, prepared the way for a great revolution. The old religion lost its hold on the higher classes; something was needed to take its place. With wealth and luxury came opportunity and desire for culture. Greece, with Art, Literature, and Philosophy fully developed and highly perfected, stood ready to instruct her rude conqueror.[1] In Cicero's time the productive era of Greek Philosophy had well-nigh passed. Its tendency was less speculative, more ethical and practical than in the earlier time. There were four prominent schools, the New Academy, the Peripatetic, the Stoic, and the Epicurean. The supporters of the last-named advocated in Science the doctrine of the atom, in Ethics the pursuit of pleasure, in Religion the complete inactivity of the gods. The Stoics and Peripatetics were divided by comparatively unimportant differences. In Ethics, considered by them as almost the whole of Philosophy, which was itself defined as 'the art of living', the main question between the two schools was the amount of importance to be attributed to Virtue,--the Stoics declaring that in comparison with Virtue all other things sink into absolute insignificance, while the Peripatetics maintained that these have a certain though infinitesimally small significance. The New Academy taught at this time no complete philosophical system. It simply proclaimed the view that in the field of knowledge certainty is unattainable, and that all the inquirer has to do is to balance probabilities one against the other. The New Academic, therefore, was free to accept any opinions which seemed to him to have the weight of probability on their side, but he was bound to be ready to abandon them when anything appeared which altered his views of the probabilities. He not only might be, but he could not help being, _eclectic_; that is, he chose such views promulgated by other schools as seemed to him at the moment to be most reasonable or probable. Cicero called himself an adherent of this school. On most points however, although eclectic, he agreed with the Peripatetics, but with a decided leaning toward the Stoic ethical system. The Stoic opinion that it is the duty of the wise man to abstain from public life, which the Peripatetics contested, Cicero decisively rejected. With the Epicureans he had absolutely no sympathy. Up to this time these schools and their teachings were known to the Romans only through the medium of the Greek.