To understand the philosophy of Cicero, it is necessary to remember both his own mental training, and the condition of those for whom he wrote. He himself regarded philosophy as food for eloquence, as one of the chief ingredients of a perfect orator. And his own mind, which by nature and practice had been cast in the oratorical mould, naturally leaned to that system which best admitted of presenting truth under the form of two competing rhetorical demonstrations. His readers, too, would be most attracted by this form of truth. He did not write for the original thinkers, the Catos, the Varros, and the Scaevolas; [62] he wrote for the great mass of intelligent men, men of the world, whom he wished to interest in the lofty problems of which philosophy treats. He therefore above all things strove to make philosophy eloquent. He read for this purpose Plato, Aristotle, and almost all the great masters who ruled the schools in his day; but being on a level with his age and not above it, he naturally turned rather to the thinkers nearest his own time, whose clearer treatment also made them most easily understood. These were chiefly Epicureans, Stoics, and Academicians; and from the different _placita_ of these schools he selected such views as harmonised with his own prepossessions, but neither chained himself down to any special doctrine, nor endeavoured to force any doctrine of his own upon others. In some of his more popular works, as those on political science and on moral duties, [63] he does not employ any strictness of method; but in his more systematic treatises he both recognises and strives to attain a regular process of investigation. We see this in the _Topica_, the _De Finibus_, and the _Tusculanae Disputationes_, in all of which he was greatly assisted by the Academic point of view which strove to reconcile philosophy with the dictates of common sense. A purely speculative ideal such as that of Aristotle or Plato had already ceased to be propounded even by the Greek systems; and Roman philosophy carried to a much more thorough development the practical tendency of the later Greek schools. In the _Hortensius_, a work unfortunately lost, which he intended to be the introduction to his great philosophical course, he removed the current objections to the study, and showed philosophy to be the only comforter in affliction and the true guide of life. The pursuit of virtue, therefore, being the proper end of wisdom, such speculations only should be pursued as are within the sphere of human knowledge. Nevertheless he is inconsistent with his own programme, for he extends his investigations far beyond the limits of ethics into the loftiest problems which can exercise the human mind. Carried away by the enthusiasm which he has caught from the great Greek sages, he asserts in one place [64] that the search for divine truth is preferable even to the duties of practical life; but that is an isolated statement.