144 HABIT AND INTELLIGENCE. [cuap. 



by introducing the conception of hereditary mental habit, 

 ^I^^'T! is due to Herbert Spencer, in whose work on Psychology 

 tlie subject is wrought out. I believe that his doctrine 

 will, in another generation or two, be universally ac- 

 cepted, and that the age-long controversy on this subject 

 will cease. 

 The It is not to be denied that space and time are forms of 



Tuted™ ' thought : the question is, how space and time have become 

 How have forms of thought. Kant repHed to this question by simply 

 spce and g^^^^.- ^^g ^Yxq fact, and stating it as an ultimate and inexplic- 

 become ^ble One. Locke and Spencer, like Kant, admit the fact ; 

 thought? but, unlike Kant, they do not regard it as ultimate and 

 ultimat^* inexplicable ; they believe, and I agree with them, that 

 or a result it is a result of experience actmg through the law of 

 encer" hereditary mental habit. 



The The doctrine that the conceptions of space and time are 



experience j.gg^its of experience is often, and conveniently, called the 

 experience theory. The doctrine that they are ultimate 

 and inexplicable laws, or forms, of thought, is often, and 

 The ideal conveniently, called the ideal theory ; and it forms a cha- 

 theory. yacteristic part of those metaphysical systems which are 

 known as the various forms of Idealism or Transcenden- 

 talism ; the essential character of which, if I understand 

 them aright, consists in regarding mind as the fundamental 

 reality, and in deriving all knowledge from the constitntion 

 of the mind itself 

 The ideal Kant's ideal doctrine, that space and time are not only 

 cousilteuT forms of thought but a priori forms — inexplicable facts of 

 with the Blind not to be accounted for by experience, or accounted 

 logy of" for at all, — this doctrine, I say, was quite consistent with 

 Kaut's ^]^g psychology of Kant's time, which regarded mind as 

 something totally distinct in nature from the matter and 

 the organic life with which it is always associated. When 

 space and time were found to be forms of thought, and 

 when thought was supposed to be something apart from the 

 external world, it was a logical inference that these forms 

 of thought belonged to the mind only, and could not be 

 traced to any origin in the external world. And it was a 

 further inference, not very obvious, but logical and perhaps 



