398 PHILOSOPHICAL THOUGHT. 



similar process of more precise definition. For the 

 purposes of the mechanical sciences, cause and effect 

 mean respectively merely the antecedent and the sub- 

 sequent in time. But this definition, which is sufficient 

 for the mechanical explanation of phenomena, and which 

 can be mathematically expressed, does not embrace 

 either the conception of the ultimate ground and 

 sufficient reason of things, or of that power, of that 

 principle of progress, of which we are conscious through 

 our Will and our actions, and which we transfer by 

 analogy to the explanation of the phenomena of growth 

 in the region of organic and mental life. 



This twofold development in quite recent times the 

 narrowing down of the meanings of the words force and 

 cause to denote such relations as can be mathematically 

 defined in terms of measurable quantities, excluding 

 actual increase or decrease has put an entirely different 

 aspect on the problem of knowledge, and has, in its 

 sequel, brought about the conception of two kinds of 

 knowledge, corresponding to the two meanings of the 

 word force and to the two meanings of the word cause. 

 We have seen that Kant took up the problem of know- 

 ledge by asking the question, How is exact knowledge 

 possible ? He started from the admitted fact that such 

 knowledge actually exists in the mathematical and 

 mechanical sciences. We have also seen how, in the 

 middle of the nineteenth century, the problem as it was 

 defined by Kant was taken up again by Mill in England 

 and by the Neo-Kantians in France and Germany. But, 

 in the meantime, the nature of this exact knowledge 

 which Kant took for granted has become more clearly 



