Though Freud was reluctant to associate his psychoanalytic insights with prior philosophical theories, attention has been drawn to analogies between his work and that of both Schopenhauer and Nietzsche, both of whom he claimed not to have read until late in life. One historian concluded, based on Freud's correspondence with his adolescent friend Eduard Silberstein, that Freud read Nietzsche's "The Birth of Tragedy" and the first two of the "Untimely Meditations" when he was seventeen. In 1900, the year of Nietzsche's death, Freud bought his collected works; he told his friend, Fliess, that he hoped to find in Nietzsche's works "the words for much that remains mute in me." Later, he said he had not yet opened them. Freud came to treat Nietzsche's writings "as texts to be resisted far more than to be studied." His interest in philosophy declined after he had decided on a career in neurology.