The friendship which grew between them was of that rare order in which neither can tell who influences the other more. Wagner would often declare that the beautiful music in the third act of Siegfried was to be ascribed to Nietzsche's influence over him; he also adopted the young man's terminology in art matters, and the concepts implied by the words "Dionysian" and "Apollonian" were borrowed by him from his friend's discourses. How much Nietzsche owed to Wagner may perhaps never be definitely known; to those who are sufficiently interested to undertake the investigation of this matter, we would recommend Hans Belart's book, Nietzsche's Ethik; in it references will be found which give some clue as to the probable sources from which the necessary information may be derived. In any case, however, the reciprocal effects of their conversations will never be exactly known; and although it would be ridiculous to assume that Nietzsche was essentially the same when he left as when he met him, what the real nature of the change was it is now difficult to say. For some years their friendship continued firm, and grew ever more and more intimate. The Birth Of Tragedy was one of the first public declarations of it, and after its publication many were led to consider that Wagner's art was a sort of resurrection of the Dionysian Grecian art. Enemies of Nietzsche began to whisper that he was merely Wagner's "literary lackey"; many friends frowned upon the promising young philologist, and questioned the exaggerated importance he was beginning to ascribe to the art of music and to art in general, in their influence upon the world; and all the while Nietzsche's one thought and one aim was to help the cause and further the prospects of the man who he earnestly believed was destined to be the salvation of European culture. Every great ideal coined in his own brain he imagined to be the ideal of his hero; all his sublimest hopes for society were presented gratis, in his writings, to Wagner, as though products of the latter's own mind; and just as the prophet of old never possessed the requisite assurance to suppose that his noblest ideas were his own, but attributed them to some higher and supernatural power, whom he thereby learnt to worship for its fancied nobility of sentiment, so Nietzsche, still doubting his own powers, created a fetich out of nis most distinguished friend, and was ultimately wounded and well-nigh wrecked with disappointment when he found that the Wagner of the Gotterdammerung and Parsifal was not the Wagner of his own mind.