"psychology from an empirical standpoint" has been compared to sigmund freud's early metapsychology, especially as expressed in his "project for a scientific psychology". paul vitz, who calls "psychology from an empirical standpoint" brentano's greatest work, notes that while brentano rejected the unconscious, "his answer followed largely from his definitions of consciousness and unconsciousness, and the evidence subsequently available to freud did not, of course, figure in brentano's thought."