14 THE ORIGIN OF HUMAN REASON. 



ourselves to controvert him, because " quod gratis 

 asseritur gratis negatur" and he has, and can have, 

 nothing but an d priori prejudice to bring forward in 

 support of his assertion. 



Because we cannot actually see or feel the origin of 

 an intellectual nature or any other nature, no argument 

 thence arises against such origins, for we have no 

 experience and can know nothing, save by rational 

 inference, of any origin whatever. It may well be that 

 there have been a countless multitude of breaks and 

 distinct origins — one even for every species — hidden 

 beneath a process of evolution that appears to be 

 continuous to our sense perceptions. Reversing, there- 

 fore, Mr. Romanes's declaration, we say, " On grounds 

 of analogy we should deem it to be antecedently 

 probable that the process of evolution at its terminal 

 phase (the advent of the rational animal — man) had 

 been interrupted because it is continually interrupted 

 now, and has notably been interrupted at the intro- 

 duction of life, and again at that of sensitivity." 



Mr. Romanes's second a priori analogical argument 

 reposes on the fact that every human individual goes 

 through " a process of gradual development and evolu- 

 tion, extending from infancy to manhood ; and that in 

 this process, which begins at a zero level of mental life 

 and may culminate in genius, there is nowhere and 

 never observable a sudden leap of progress, such as the 

 passage from one order of psychical being to another 

 might reasonably be expected to show. Therefore," 

 he adds, " it is a matter of observable fact that, whether 

 or not human intelligence differs from animal in kind, 



