When Nietzsche renounced the musical career, in order to devote himself to philology, and gave himself up to the most strenuous study, he did not find it essential completely to suppress his other tendencies: as before, he continued both to compose and derive pleasure from music, and even studied counterpoint somewhat seriously. Moreover, during his years at Leipzig, when he consciously gave himself up to philological research, he began to engross himself in Schopenhauer, and was thereby won by philosophy for ever. Everything that could find room took up its abode in him, and these juxtaposed factors, far from interfering with one another's existence, were rather mutually fertilising and stimulating. All those who have read the first volume of the biography with attention must have been struck with the perfect way in which the various impulses in his nature combined in the end to form one general torrent, and how this flowed with ever greater force in the direction of _a single goal._ Thus science, art, and philosophy developed and became ever more closely related in him, until, in _The Birth of Tragedy,_ they brought forth a "centaur," that is to say, a work which would have been an impossible achievement to a man with only a single, special talent. This polyphony of different talents, all coming to utterance together and producing the richest and boldest of harmonies, is the fundamental feature not only of Nietzsche's early days, but of his whole development. It is once again the artist, philosopher, and man of science, who as one man in later years, after many wanderings, recantations, and revulsions of feeling, produces that other and rarer Centaur of highest rank--_Zarathustra_. _The Birth of Tragedy_ requires perhaps a little explaining--more particularly as we have now ceased to use either Schopenhauerian or Wagnerian terms of expression. And it was for this reason that five years after its appearance, my brother wrote an introduction to it, in which he very plainly expresses his doubts concerning the views it contains, and the manner in which they are presented. The kernel of its thought he always recognised as perfectly correct; and all he deplored in later days was that he had spoiled the grand problem of Hellenism, as he understood it, by adulterating it with ingredients taken from the world of most modern ideas. As time went on, he grew ever more and more anxious to define the deep meaning of this book with greater precision and clearness. A very good elucidation of its aims, which unfortunately was never published, appears among his notes of the year 1886, and is as follows:--