COMMON BASIS OF EMPIRICISM AND RATIONALISM 19 



distinguish than one at rest, so the developing organism reveals 

 the intricacies of its structure far more easily than the same 

 organism studied at only a single stage of its life-history. And 

 so also the philosophical conceptions, which to our direct exami- 

 nation appear to be inexplicable intuitions of the human mind, 

 may exhibit their hidden content with the greatest clearness 

 when the record of their various metamorphoses lies before us. 

 Thus the question of deepest interest is not : "How far can Plato's 

 thought be made to square with the science of today?" but rather: 

 "How far has Plato's thought entered into the living tissue of the 

 science of today?" The most valuable criticism, therefore, is 

 contained in a plain and clear exposition. The best refutation 

 of a theory is the unvarnished history of its transformations. 



To many of our readers all that we have just now been saying 

 must appear to be sheer truism; and very few will question its 

 substantial correctness. It may, therefore, be thought worthy 

 of note, that not one of the writers whom we have mentioned 

 would have found a word of truth in the whole discussion. No 

 feature, in fact, is more characteristic of the old dogmatism than 

 the general incapacity of thinkers of both schools to recognize 

 the fact (or the possibility) of an evolutionary progress of human 

 knowledge. If science should advance, it must be by the addition 

 of new truths to old. That half-truths might grow into whole 

 ones was unsuspected. As truth w T as absolute truth, so error 

 was absolute error; and as the former was most advantageous, 

 so the latter (whether avoidable or unavoidable) was most detri- 

 mental, to the acquirement of further truth. 



Of the rationalists this holds true as a matter of course. The 

 very essence of anti-evolutionism is expressed by Spinoza in his 

 letter to a recreant pupil: "I do not presume that I have found 

 the best philosophy, I know that I understand the true philos- 

 ophy. If you ask in what way I know it, I answer: In the same 

 way as you know that the three angles of a triangle are equal to 

 two right angles." 1 It is not a question of comparisons! But 



1 Letter LXXIV, Elwes tr 



