424 THE POPULAR SCIENCE MONTHLY. 



given of all the factors individually considered. So is it, too, with 

 the physicist. Say the problem is the propagation of sound through 

 air, and the interpretation of its velocity say that the velocity as 

 calculated by Newton is found less by one-sixth than observation 

 gives, and that Laplace sets himself to explain the anomaly. He rec- 

 ognizes the evolution of heat by the compression which each sound- 

 wave produces in the air; finds the extra velocity consequent on this ; 

 adds this to the velocity previously calculated ; finds the result an- 

 swer to the observed fact ; and then, having analyzed the phenomenon 

 into its components and measured them, considers his task concluded. 

 So throughout : the habit is that of identifying, parting, and estimat- 

 ing factors, and stopping after having done this completely. 



This habit, carried into the interpretation of things at large, affects 

 it somewhat as the mathematical habit affects it. It tends toward the 

 formation of unduly-simple and unduly-definite conceptions ; and it 

 encourages the natural propensity to stop short with proximate results. 

 The daily practice of dealing with single factors of phenomena, and 

 with factors complicated by but few others, and with factors ideally 

 separated from their combinations, inevitably gives to the thoughts 

 about surrounding things an analytic rather than a synthetic character. 

 It promotes the contemplation of simple causes apart from the entan- 

 gled plexus of cooperating causes which all the higher natural phe- 

 nomena show us, and begets a tendency to suppose that, when the 

 results of such simple causes have been exactly determined, nothing 

 remains to be sought. 



Physical science, then, though indispensable as a means of develop- 

 ing the consciousness of causation in its simple definite forms, and thus 

 preparing the mind for dealing with complex causation, is not sufficient 

 of itself to make complex causation truly comprehensible. In illus- 

 tration of its inadequacy, I might name a distinguished mathematician 

 and physicist whose achievements place him in the first rank, but who, 

 nevertheless, when entering on questions of concrete science, where 

 the data are no longer few and exact, has repeatedly shown defective 

 judgment. Choosing premisses which, to say the least, were gratui- 

 tous and in some cases improbable, he has proceeded by exact methods 

 to draw definite conclusions, and has then enunciated those conclu- 

 sions as though they had a certainty proportionate to the exactness of 

 his methods. 



The kind of discipline which affords the needful corrective is the 

 discipline which the Concrete Sciences give. Study of the forms of 

 phenomena, as in Logic and Mathematics, is needful, but by no means 

 sufficient. Study of the factors of phenomena, as in Mechanics, Phys- 

 ics, Chemistry, is also essential, but not enough by itself, or enough 

 even joined with study of the forms. Study of the products them- 

 selves, in their totalities, is no less necessary. Exclusive attention to 

 forms and factors will not only fail to give right conceptions of prod- 



