340 SCIENTIFIC THOUGHT. 



and arguments on both sides of each question." l It is 

 quite a different process of investigation and method of 

 thought from that which the abstract sciences use, where 

 every agency is first considered in its isolated action and 

 mathematically calculated, and a complex effect is rightly 

 looked upon as merely the resultant of specific, well- 

 defined forces, compounded according to rigid dynamical 

 formula. That the whole of nature, as well as all 

 observable phenomena, are in reality only the result of 

 such a composition of definite simple actions, and can be 

 studied as such, may be quite correct ; but that this 

 method, however useful in isolated cases, and especially 

 however fruitful in the application to artificial mechanisms, 

 will never lead to a just comprehension of any large 

 cluster of phenomena, or to an appreciation of the totality 

 of things which surround us, must be evident to any one 

 who at once appreciates the rigidity and universality of 

 mathematical calculations, and sees how soon they fail to 

 become of practical use when we attempt to attack any 

 complex problem through them. Now, all processes in 

 nature herself, as distinguished from the laboratory, are 

 eminently complex, and far transcend the powers and 

 grasp of the mathematical calculus, so far as the human 

 mind is able to employ it. In fact, the outdoor 

 naturalist must attack the problem of nature and life 

 by quite a different method : he must, like a judge, con- 

 front and appreciate the evidence of many witnesses 

 who are speaking on all sides to him, and he must, 

 with an open and unbiassed mind, judiciously combine 

 such evidence in the sentences which he passes or the 



1 ' Origin of Species,' 1st ed., p. 2. 



