Diogenes Laertius reports the story of Socrates having dreamed he found an unfledged cygnet on his knee. In a few moments it became winged and flew away, uttering a sweet sound. The next day a young man came to him who was said to reckon Solon among his near ancestors, and who looked, through him, to Codrus and the god Poseidon. That young man was Plato, and Socrates pronounced him to be the bird he had seen in his dream.[489] [Footnote 489: Diogenes Laertius, "Lives of the Philosophers," bk. iii. ch. vii.] Some have supposed that this old tradition intimates that Plato departed from the method of his master--he became fledged and flew away into the air. But we know that Plato did not desert his master whilst he was living, and there is no evidence that he abandoned his method after he was dead. He was the best expounder and the most rigid observer of the Socratic "organon." The influence of Socrates upon the philosophy of Plato is everywhere discernible. Plato had been taught by Socrates, that beyond the world of sense there is a world of eternal truth, seen by the eye of reason alone. He had also learned from him that the eye of reason is purified and strengthened by _reflection_, and that to reflect is to observe, and analyze, and define, and classify the facts of consciousness. Self-reflection, then, he had been taught to regard as the key of real knowledge. By a completer induction, a more careful and exact analysis, and a more accurate definition, he carried this philosophic method forward towards maturity. He sought to solve the problem of _being_ by the principles revealed in his own consciousness, and in the _ultimate ideas of the reason_ to find the foundation of all real knowledge, of all truth, and of all certitude.