CONTENT AND VALIDITY OF THE CAUSAL LAW 381 



in the special case. It contains, as we might also express it, the 

 genus to the specific limitations of the more exact investigation. 

 But each of these general hypotheses is a modification of the most 

 general form of building hypotheses, which we have already come 

 to know as the condition of the validity of all inductive inferences, 

 that is, as the condition for the necessity of their deduction, and, 

 consequently, as the condition for the thought that like causes will 

 be given in the reality not yet observed as in that already observed. 

 We have further noticed that in this most general form of building 

 hypotheses there lie two distinct and different valid assumptions: 

 beside the empirical statement that like causes will be given, which 

 gives the inductive conclusion the hypothetical form, there stands 

 the judgment that like causes bring forth like effects, a corollary of 

 the causal law. The real dependence of the effect upon the cause, 

 presupposed by this second proposition and the underlying causal 

 law, is not, as was the other assumption, an hypothesis, but a neces- 

 sary requirement or postulate of our thought. Its necessity arises out 

 of our thought, because our experience reveals uniformity in the 

 sequence of events. From this point of view, therefore, the causal 

 law appears as a postulate of our thought, grounded upon the uni- 

 formity in the sequence of events. It underlies every special case of 

 constructing hypotheses as well as the expectation that like causes 

 will be given in the reality not yet observed. 



Mill's logic of induction contains the same fault as that already 

 present in Hume's psychological theory of cause. Hume makes 

 merely the causal law itself responsible for our inductive inferences, 

 and accordingly (as Mill likewise wrongly assumes) for our inferences 

 in general. But we recognize how rightly Mill came to assert, in 

 contradiction to his empiristic presuppositions, that the causal law 

 offers "an undoubted assurance of an invariable, universal, and 

 unconditional," that is, necessary, sequence of events, from which 

 no seeming irregularity of occurrence and no gap in our experience 

 can lead us astray, as long as experience offers uniformities of se- 

 quence. 



Rationalism is thus in the right, when it regards the necessary 

 connection as an essential characteristic of the relation between 

 cause and effect, that is, recognizes in it a relation of real dependence. 

 At this point Kant and Schopenhauer have had a profounder insight 

 than Hume and Stuart Mill. Especially am I glad to be in agreement 

 with Lotze on a point which he reached by a different route and 

 from essentially different presuppositions. Lotze distinguishes in 

 pure logic between postulates, hypotheses, and fictions. He does 

 not refer the term "postulate" exclusively to the causal law which 

 governs our entire empirical thought in its formation of hypotheses, 

 but gives the term a wider meaning. " Postulates " are only corollaries 



