It was, however, chiefly that remarkable series of philosophers which may be grouped under the rubric of a "rational Idealism," who filled so full and made so rich the philosophical life of Germany during the first half of the last century; whose philosophical thoughts and systems have spread over the entire Western World, and who are most potent influences in shaping the development of philosophy down to the present hour. Of these we need do little more than that we can do--mention their names. At their head, in time, stands Fichte, who--although Kant is reported to have complained of this disciple because he lied about him so much--really divined a truth which seems to be hovering in the clouds above the master's head, but which, if the critical philosophy truly meant to teach it, needed helpful deliverance in order to appear in perfectly clear light. Fichte, although he divined this truth, did not, however, free it from internal confusion and self-contradiction. It _is_ his truth, nevertheless, that in the Self, as a self-positing and self-determining activity, must somehow be found the Ground of all experience and of all Reality.
The important note which Schelling sounded was the demand that philosophy should recognize "Nature" as belonging to the sphere of Reality, and as requiring a measure of reflective thought which should in some sort put it on equal terms with the Ego, for the construction of our conception of the Being of the World. To Schelling it seemed impossible to deduce, as Fichte had done, all the rich concrete development of the world of things from the subjective needs and constitutional forms of functioning which belong to the finite Self. And, indeed, the doctrine which limits the origin, existence, and value of all that is known about this sphere of experience to these needs, and which finds the sufficient account of all experience with nature in these forms of functioning, must always seem inadequate and even grotesque in the sight of the natural sciences. Both Nature and Spirit, thought Schelling, must be allowed to claim actual existence and equally real value; while at the same time philosophy must reconcile the seeming opposition of their claims and unite them in an harmonious and self-explanatory way. In some common substratum, in which, to adopt Hegel's sarcastic criticism, as in the darkness of the night "all cows are black,"--that is in the Absolute, as an Identical Basis of Differences,--the reconciliation was to be accomplished.