Also contrary to his mother's prediction, Schopenhauer's dissertation made an impression on Goethe to whom he sent it as a gift. Although it is doubtful that Goethe agreed with Schopenhauer's philosophical positions he was impressed by his intellect and extensive scientific education. Their subsequent meetings and correspondence were a great honor to a young philosopher who was finally acknowledged by his intellectual hero. They mostly discussed Goethe's newly published (and somewhat lukewarmly received) work on color theory. Schopenhauer soon started writing his own treatise on the subject, "On Vision and Colors", which in many points differed from his teacher's. Although they remained polite towards each other, their growing theoretical disagreements—and especially Schopenhauer's tactless criticisms and extreme self-confidence—soon made Goethe become distant again and after 1816 their correspondence became less frequent. Schopenhauer later admitted that he was greatly hurt by this rejection, but he continued to praise Goethe, and considered his color theory a great introduction to his own.