i2 4 THE POPULAR SCIENCE MONTHLY 



as with Berkeley, so with the others; for example, he never quite gets 

 hold of Kant's phenomenalism. It is Hume, however, who, through 

 that analysis of causation which made him famous and which con- 

 stitutes the basis for the logic of induction, is of dominant influence 

 on Professor Brooks. The results which Hume obtained are, as is 

 generally well known: (1) that, tracing our concept of cause back 

 to its origin in perception, there is given here only sequential and 

 factual but never necessary connection; (2) that, however, from the 

 experience of frequently repeated specific sequences, a belief in their 

 regular and uniform and even necessary occurrence is generated, or, 

 more generally, that a belief in a universal, necessary order is formed. 

 (3) The belief is justified and is of value practically, but neverthe- 

 less, that there is a universal and necessary regularity or order is a pure 

 assumption, or (Mill) it is itself that generalization, by induction from 

 a limited number of cases, which lies at the basis of all specific induc- 

 tions and gives the " inductive syllogism." All this means that, 

 although a purely deductive theoretical mechanics as = " the geom- 

 etry of motion " is possible and as siich may be identified with de- 

 terminism, this can be applied to nature only by finding the numerical 

 values for certain functions or properties or qualities experimentally 

 and factually. It means, accordingly, that in just this respect nature is 

 not deductive, is not determined, and that the view that it is " order " 

 is an assumption neither proved nor provable. This does not mean 

 that the same cause under the same conditions does not bring about the 

 same effect; it may, or it may not, but that this is the case is simply 

 the same assumption over again. 



It is on the basis of this criticism and analysis of causation, of 

 " order," etc., that Professor Brooks discusses very interestingly such 

 topics as the " Philosophy of Evolution," " Paley and the Argument 

 from Contrivance," " The Mechanism of Nature," etc. If mechanism 

 is to be equated with determinism and " order " — and that is all that 

 it really means to the majority of biologists as well as to the majority 

 of people — then it also is, like them, as above explained, only a pure 

 assumption. But the possibilities or consequences resulting from this 

 are interesting and important. For, with it unproved that there is that 

 kind of continuity and causation and " order " and determinism which 

 would make a purely deductive knowledge possible, there is the logically 

 valid opportunity for spontaneity and genuine discontinuous origin and 

 freedom and teleology and purpose; and yet all of these are quite con- 

 sistent with that other view of " order," etc., which means that, when 

 specific instances of these have once been discovered by induction, the 

 presumption and the probability is that under the same conditions they 

 will recur. But this simply means that there is a genuine evolution 

 and advance which is at once compatible with mechanism in the above 



