MENTAL LIFE 



comprehensive groups of association. In the scientific 

 life of the mind, therefore, the intelligence is always 

 occupied with empirical investigation, and reason with 

 speculative knowledge. But the two faculties are 

 equally functions of the phronema, and depend on the 

 normal anatomic and chemical condition of this organ 

 of thought. 



Since Kant won so great a prominence in modern 

 philosophy for the idea of pure reason by his famous 

 Critique (1781), it has been much discussed, especially in 

 the modern metaphysical theory of knowledge. It has, 

 however, like all other ideas, undergone considerable 

 changes of meaning in the course of time. Kant himself 

 at first understood by pure reason "reason independent 

 of all experience." But impartial modern psychology 

 based on the physiology of the brain and the phylogeny 

 of its functions, has shown that there is no such thing as 

 this pure a priori knowledge, independent of all experi- 

 ence. Those principles of reason which at present seem 

 to be a priori in this sense have been attained in virtue 

 of thousands of experiences. In so far as this is a ques- 

 tion of real knowledge of the truth, Kant himself has 

 frequently recognized the point. He says expressly in 

 his Prolegomena to any future metaphysic that can be 

 regarded as Science (1783, p. 204): "A knowledge of 

 things by pure reason or pure intelligence is nothing 

 but an empty appearance; only in experience is there 

 truth." In subscribing to this empirical theory of 

 knowledge of Kant I. and rejecting the transcendental 

 theory of Kant II., we may on our side understand by 

 pure reason "knowledge without prejudices," free from 

 all dogma — all fictions of faith. 



The familiar cry of modern metaphysicians, "Return 

 to Kant," has become so general in Germany that not 

 only nearly all metaphysicians — the official representa- 

 tives of "philosophy" at our universities — but also 



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