Whilst, then, Socrates was not the first to teach the doctrine of immortality, because no one could be said to have first _discovered_ it any more than to have first discovered the existence of a God, he was certainly the first to place it upon a philosophic basis. The Phædo presents the doctrine and the _reasoning_ by which Socrates had elevated his mind above the fear of death. Some of the arguments may be purely Platonic, the argument especially grounded on "ideas;" still, as a whole, it must be regarded as a tolerably correct presentation of the manner in which Socrates would prove the immortality of the soul. In _Ethics_, Socrates was pre-eminently himself. The systematic resolution of the whole theory of society into the elementary principle of natural law, was peculiar to him. _Justice_ was the cardinal principle which must lie at the foundation of all good government. The word σοφια--_wisdom_--included all excellency in personal morals, whether as manifested (reflectively) in the conduct of one's self, or (socially) towards others. And _Happiness_, in its purity and perfection, can only be found in virtuous action.[486] [Footnote 486: Butler's "Lectures on Ancient Philosophy," vol. i. pp. 360, 361.] Socrates left nothing behind him that could with propriety be called a _school_. His chief glory is that he inaugurated a new _method_ of inquiry, which, in Plato and Aristotle, we shall see applied. He gave a new and vital impulse to human thought, which endured for ages; "and he left, as an inheritance for humanity, the example of a heroic life devoted wholly to the pursuit of truth, and crowned with martyrdom." CHAPTER X. THE PHILOSOPHERS OF ATHENS (_continued_). THE SOCRATIC SCHOOL (_continued_). PLATO. We have seen that the advent of Socrates marks a new era in the history of speculative thought. Greek philosophy, which at first was a philosophy of nature, now changes its direction, its character, and its method, and becomes a philosophy of mind. This, of course, does not mean that now it had mind alone for its object; on the contrary, it tended, as indeed philosophy must always tend, to the conception of a rational ideal or _intellectual system of the universe_. It started from the phenomena of mind, began with the study of human thought, and it made the knowledge of mind, of its ideas and laws, the basis of a higher philosophy, which should interpret all nature. In other words, it proceeded from psychology, through dialectics, to ontology.[487] [Footnote 487: Cousin's "Lectures on the History of Philosophy," vol. i. p. 413.]