575.2 231 



The Study of Variations 



THE work of any generation must be largely influenced by 

 current accepted ideas, which form, as it were, a mental 

 environment, with which all the work of that generation will be 

 coloured, and it follows that there must be considerable danger 

 resulting from reactionary tendencies which frequently arise 

 when the preceding generation has carried any given method of 

 research beyond warrantable limits. If these current ideas do not 

 happen to be true, errors, which may take years to eradicate, may 

 arise, owing to theories being built upon these faulty conceptions. 

 Harmful as this must be, it is, I believe, far less so than when a 

 definite feeling or prejudice is formed in the mind against some 

 method which had been previously misused. 



For any prejudice thus formed will necessarily influence all 

 work produced by all the minds so affected, and, further, while it 

 is possible conclusively to disprove any erroneous idea, it is ex- 

 tremely difficult to remove any prejudice of the mind, when once 

 formed. 



In the present age it will, I believe, be found on reflection that 

 the tendency, in all branches of science, is to neglect all purely 

 theoretical conceptions, however sound, and to rely exclusively on 

 practical deductions, for the most part directly deduced from ex- 

 periment. This contempt for theory is, to my thinking, one of the 

 most unsatisfactory elements in modern science, and has probably 

 been directly induced by the extremely speculative and untrust- 

 worthy theories of the beginning of this and the latter part of the 

 last century. 



A theory of some sort is necessary to enable any investigator to 

 collect facts or to perform experiments to any purpose, for facts or 

 experiments, however numerous, are useless if any important factor 

 is not accounted for, hence increasingly definite conceptions or 

 theories always precede increasingly trustworthy investigation. 



" It is a common error," says Poulton,^ " to suppose that the 

 intellectual powers, which make the poet or the historian, are 

 essentially different from those which make the man of science. 

 Powers of observation, however acute, could never make a scientific 



^ " Charles Darwin and the Theory of Natural Selection." 



