Vernünfftige Gedancken von Gott, der Welt und der Seele des Menschen, auch allen Dingen überhaupt -- Christian Freyherrn von Wolf Erinnerung, wie er es künftig mit den Einwürfen halten will, die wider seine Schriften gemacht werden.

Together with other influential psychologists of the time, Wundt considers internal data as absolute evidence, grounding psychology on this assumption. In opposition to his former mentor, Külpe aims at rehabilitating Kant’s transcendental aesthetics. Yet, he is far from embracing transcendentalism and rejects Kant’s skepticism as to the possibility of a scientific psychology. Nevertheless, Külpe believes that Kant is right in considering internal data as unreliable for scientific purposes: accordingly, psychology should share the same scientific methodology of any other science.