194 SOME ANALOGIES PRESENTED. 



versa, we feel temporarily blinded : the eye demands a short 

 time to recover, as it were, from its astonishment. If we fix 

 our gaze for one or two minutes on a star of the first magni- 

 tude, as, for example, Sirius, and afterwards turn away abruptly, 

 the eye will for a while remain insensible to stars of a less in- 

 tense splendour. 



These are incontestable physiological facts, which anybody 

 may easily verify for himself. 



Well, in the psychological order facts exist which are in all 

 respects analogous. Take one of those truths which the 

 human thought, labouring generation after generation, has 

 taken centuries to discover or elucidate; place it suddenly 

 before an unprepared mind; however luminous may be this 

 truth, it will be simply shadow and darkness to the mind we 

 speak of ; it will not comprehend an iota of it. Why ? For 

 the very obvious reason that it lies outside its sphere of ideas, 

 in every respect comparable to the sphere of vision, beyond 

 which and within which there is no more room for the sen- 

 sorial impressions. There, as here, we must proceed gradually, 

 and arrange the transitions so as to produce the desired results. 



It would be easy for me to develop this parallel by other 

 and still more remarkable facts; but what I have just said 

 will suffice to show that the line of demarcation which philo- 

 sophers have, upon principle, desired to trace between the 

 physical and moral order, has turned the mind aside from 

 many fertile fields of research and speculation. Let us cite 



