(b) Was he justified in assuming that all the ordering of our world is due to the activity of mind, and that merely the raw material is “given” us through the senses?  There are many who demur against such a statement, and hold that it is, if not in all senses untrue, at least highly misleading, since it seems to argue that there is no really external world at all.  Moreover, they claim that the doctrine is neither self-evident nor susceptible of proper proof.

(c) Was Kant justified in assuming that, even if we attribute the “form” or arrangement of the world we know to the native activity of the mind, the necessity and universality of our knowledge is assured?  Let us grant that the proposition, whatever happens must have an adequate cause, is a “form of thought.”  What guarantee have we that the “forms of thought” must ever remain changeless?  If it is an assumption for the empiricist to declare that what has been true in the past will be true in the future, that earlier experiences of the world will not be contradicted by later; what is it for the Kantian to maintain that the order which he finds in his experience will necessarily and always be the order of all future experiences?  Transferring an assumption to the field of mind does not make it less of an assumption.

Thus, it does not seem unreasonable to charge Kant with being a good deal of a rationalist.  He tried to confine our knowledge to the field of experience, it is true; but he made a number of assumptions as to the nature of experience which certainly do not shine by their own light, and which many thoughtful persons regard as incapable of justification.

Kant’s famous successors in the German philosophy, Fichte (1762-1814), Schelling (1775-1854), Hegel (1770-1831), and Schopenhauer (1788-1860), all received their impulse from the “critical philosophy,” and yet each developed his doctrine in a relatively independent way.

I cannot here take the space to characterize the systems of these men; I may merely remark that all of them contrast strongly in doctrine and method with the British philosophers mentioned in the last section, Locke, Berkeley, Hume, and Mill.  They are un-empirical, if one may use such a word; and, to one accustomed to reading the English philosophy, they seem ever ready to spread their wings and hazard the boldest of flights without a proper realization of the thinness of the atmosphere in which they must support themselves.

However, no matter what may be one’s opinion of the actual results attained by these German philosophers, one must frankly admit that no one who wishes to understand clearly the development of speculative thought can afford to dispense with a careful reading of them.  Much even of the English philosophy of our own day must remain obscure to those who have not looked into their pages.  Thus, the thought of Kant and Hegel molded the thought of Thomas Hill Green (1836-1882) and of the brothers Caird; and their influence has made itself widely felt both in England and in America.  One cannot criticise intelligently books written from their standpoint, unless one knows how the authors came by their doctrine and out of what it has been developed.