These theoretical advantages of idealism are supplemented by momentous reasons of a practical kind, which determine the choice between the two systems, besides which none other is possible.  The moral law says:  Thou shalt be self-dependent.  If I ought to be so I must be able to be so; but if I were matter I would not be able.  Thus idealism proves itself to be the ethical mode of thought, while the opposite mode shows that those who favor it have not raised themselves to that independence of all that is external which is morally enjoined, for in order to be able to know ourselves free we must have made ourselves free.[1] Thus the philosophy which a man chooses depends on what sort of a man he is.  If, on the other hand, the categorical imperative calls for belief in the reality of the external world and of other minds, this is nothing against idealism.  For idealism does not deny the realism of life, but explains it as a necessary, though not a final, mode of intuition.  The dogmatic mode of thought is merely an explanation from the standpoint of common consciousness, and for idealism, as the only view which is both scientifically and practically satisfactory, this explanation itself needs explaining.  Realism and idealism, like natural impulse and moral will in the sphere of action, are both grounded in reason.  But idealism is the true standpoint, because it is able to comprehend and explain the opposing theory, while the converse is not the case.

[Footnote 1:  Cf.  O. Liebmann (Ueber den individuellen Beweis fuer die Freiheit des Willens p, 131. 1866) “Here we discover the noteworthy point where theoretical and practical philosophy actually pass over into each other.  For this principle results:  In order to carry out the individual proof for the freedom of the will, I must do my duty.”]

The nature, the goal, and the methods of the Science of Knowledge have now been determined.  It is genuine, thoroughgoing idealism, which raises the Kantian philosophy to the rank of an evident science by deducing its premises from a first principle which is immediately certain, and by removing the twofold dualism of intuition and thought, of knowledge and volition, viz., by proving both contraries acts of one and the same ego.  While Reinhold had sought a supreme truth as a fundamental principle of unity, without which the doctrine of knowledge would lack the systematic form essential to science, while Beck had interpreted the spirit of the Kantian philosophy in an idealistic sense, and Jacobi had demanded the elimination of the thing in itself, all these desires combined are fulfilled in Fichte’s doctrine, and at the same time the results of the Critique of Reason are given that evidence which Aenesidemus-Schulze had missed in them.  As an answer to the question, “How is knowledge brought about?” (as well the knowledge of common sense as that given in the particular sciences), “how is experience possible?”, and as a construction of common