CONTENT AND VALIDITY OF THE CAUSAL LAW 375 



abstract registering idea of uniform sequence. We may, therefore, 

 expect to find that the element sought for lies in the tendency to 

 extend the demand for causal connections over the entire field of 

 possible experience; and perhaps we may at the same time arrive 

 at the condition which led Hume and Mill to recognize the complete 

 universality of the causal law in spite of the exclusively empirical 

 content that they had ascribed to it. In this further analysis also 

 we have to draw from the nature of our thought itself the means of 

 guiding our investigation. 



In the first place, all thought has a formal necessity which reveals 

 itself in the general causal law no less than in every individual 

 thought process, that is, in every valid judgment. The meaning of 

 this formal necessity of thought is easily determined. If we presup- 

 pose, for example, that I recognize a surface which lies before me 

 as green, then the perception judgment, "This surface is green," 

 that is, the apprehension of the present perceptive content in the 

 fundamental form of discursive thought, repeats w r ith predicative 

 necessity that which is presented to me in the content of perception. 

 The necessity of thought contained in this perception judgment, as 

 mutatis mutandis in every affirmative judgment meeting the logical 

 conditions, is recognizable through the fact that the contradictory 

 judgment, "This surface is not green," is impossible for our thought 

 under the presupposition of the given content of perception and of 

 our nomenclature. It contradicts itself. I can express the contradict- 

 ory proposition, for instance, in order to deceive; but I cannot really 

 pass the judgment that is contained in it. It lies in the very nature 

 of our thought that the predicate of an assertive judgment can con- 

 tain only whatever belongs as an element of some sort (characteristic, 

 attribute, state, relation) to the subject content in the wider sense. 

 The same formal necessity of thought, to give a further instance, is 

 present in the thought process of mediate syllogistic predication. 

 The conclusion follows necessarily from the premises, for example, 

 the judgment, "All bodies are divisible," from the propositions, 

 " All bodies are extended," and, " Whatever is extended is divisible." 



These elementary remarks are not superfluous; for they make 

 clear that the casually expressed assertion of modern natural scien- 

 tific empiricism, declaring in effect that there is no such thing as 

 necessity of thought, goes altogether too far. Such necessity can 

 have an admissible meaning only in so far as it denotes that in 

 predicting or recounting the content of possible experience every hypo- 

 thesis is possible for thought. Of course it is, but that is not 

 the subject under discussion. 



The recognition of the formal necessity of thought that must be 

 presupposed helps us to define our present question; for it needs no 

 proof that this formal necessity of thought, being valid for every 



