The German thinker, who has given perhaps the most fruitful stimulus to the scientific study of psychology in modern times—Johann Friedrich Herbart—is after all essentially a philosopher, and not a mere scientist, even in his psychology. His psychological inquiry, that is, stands in intimate connexion with the last questions of all intelligence, with metaphysics and ethics. The business of philosophy, says Herbart, is to touch up and finish off conceptions (_Bearbeitung der Begriffe_)(22). It finds, as it supervenes upon the unphilosophical world, that mere and pure facts (if there ever are or were such purisms) have been enveloped in a cloud of theory, have been construed into some form of unity, but have been imperfectly, inadequately construed: and that the existing concepts in current use need to be corrected, supplemented and readjusted. It has, accordingly, for its work to “reconcile experience with itself(23),” and to elicit “the hidden pre-suppositions without which the fact of experience is unthinkable.” Psychology, then, as a branch of this philosophic enterprise, has to readjust the facts discovered in inner experience. For mere uncritical experience or merely empirical knowledge only offers _problems_; it suggests gaps, which indeed further reflection serves at first only to deepen into contradictions. Such a psychology is “speculative”: i.e. it is not content to accept the mere given, but goes forward and backward to find something that will make the fact intelligible. It employs totally different methods from the “classification, induction, analogy” familiar to the logic of the empirical sciences. Its “principles,” therefore, are not given facts: but facts which have been manipulated and adjusted so as to lose their self-contradictory quality: they are facts “reduced,” by introducing the omitted relationships which they postulate if they are to be true and self-consistent(24). While it is far from rejecting or ignoring experience, therefore, psychology cannot strictly be said to build upon it alone. It uses experimental fact as an unfinished datum,—or it sees in experience a torso which betrays its imperfection, and suggests completing.