CONTENT AND VALIDITY OF THE CAUSAL LAW 377 



event a, which determines necessarily the constant subsequent 

 appearance of one and the same b, - - that is, if there is nothing 

 fundamental which makes this appearance necessary, -- then we 

 must assume that also c or d . . . , in short, any event you will, 

 we dare not say "follows upon," but appears after a in irregular 

 alternation with b. This assumption, however, is impossible for our 

 thought, because it is in contradiction with our experience, on the 

 basis of which our causal thought has been developed. Therefore 

 the assumption of a something that is fundamental in a, and that 

 determines sufficiently and necessarily the appearance of b, is a 

 necessity for our thought. 



The assertion of this logical impossibility (Denkunmoglichkeit) 

 will at once appear thoroughly paradoxical. The reader, merely 

 recalling the results of the empiristic interpretation given above, 

 will immediately say: "The assumption that a b does not follow 

 constantly upon an a, but that sometimes b, sometimes c, some- 

 times d . . . irregularly appears, is in contradiction only with all 

 our previous experience, but it is not on this account a logical im- 

 possibility. It is merely improbable." The reader will appeal espe- 

 cially to the discussion of Stuart Mill, already quoted, in which Mill 

 pictures in concreto such an improbable logical impossibility, and 

 therefore at the same time establishes it in fact. Again, the reader 

 may bring forward the words in which Helmholtz introduces intel- 

 lectual beings of only two dimensions. "By the much misused 

 expression, 'to be able to imagine to one's self,' or, 'to think how 

 something happens,' I understand (and I do not see how anybody 

 can understand anything else thereby without robbing the expression 

 of all meaning) that one can picture to one's self the series of sense 

 impressions which one would have if such a thing actually took 

 place in an individual case." 1 



Nevertheless, pertinent as are these and similar objections, they 

 are not able to stand the test. We ask: "Is in fact a world, or even 

 a portion of our world, possible for thought that displays through an 

 absolutely irregular alternation of events a chaos in the full sense; 

 or is the attempt to picture such a chaos only a mere play of words 

 to which not even our imagination, not to mention our thought, can 

 give a possible meaning? " 



Perhaps we shall reach a conclusion by the easiest way, if we 

 subject Mill's description to a test. If we reduce it to the several 

 propositions it contains, we get the following: (1) Every one is able 

 to picture to himself in his imagination a reality in which events 

 follow one another without rule, that is, so that after an event a 

 now b appears, now c, etc., in complete irregularity. (2) The idea of 



1 Vortrage und Reden, bd. n, "Uber den Ursprung und die Bedeutung der 

 geometrischen Axiome." 



