 At the very end of his autobiography, Stumpf confesses that he never sought to establish a school and that he is grateful to those of his students who pursued their research based on their own plans in the same scientific spirit. Stumpf’s words are confirmed by the testimonies of many of his students who all shared this scientific spirit and described Stumpf as a model of precision and clarity in thought and observation, with a keen sense for analysis and a critical attitude towards his own philosophical thought. If indeed he did not establish a school, he is however responsible for the formation of outstanding researchers and philosophers, and he has contributed directly to the development of two of the most important movements in Germany at the beginning of the twentieth century: Gestalt psychology and phenomenology. But Stumpf also counts as one of the harshest critics of these two movements as evidenced in his Erkenntnislehre, a posthumous work in which he presents the essential elements of his Weltanschauung and, in a sense, his philosophical testament. Let us remember that this book is dedicated to Brentano and can therefore be considered a contribution, the last in importance in the school of Brentano, to the philosophical program of his mentor. It is not surprising, therefore, that the criticism he addressed to his own students in this work was mainly motivated by this program.