4l6 ON SENSORIAL VISION. 



always succeed, and requires a peculiar adjustment 

 of the light, and of the comparative illumination of the 

 objects and the ground on which it is seen projected, 

 and perhaps also a peculiar state of nerve ; but Avhen it 

 does succeed, the effect is exceedingly singular and 

 anomalous. 



(20.) It would lead me into too great a length of detail, 

 and I may also add, into a labyrinth of metaphysical 

 considerations, out of which I should find some diffi- 

 culty of getting disentangled, if I were to go into a dis- 

 cussion on those points of connexion between our 

 mental and our bodily organization which these facts 

 seem to suggest. There is a very curious chapter in 

 Stuart Mill's Ti-eatise on Logic, devoted to the question 

 whether we are quite sure that every event /las a cause. 

 He decides it, as every reasonable man must do, in 

 favour of the universality of the proposition, but he is 

 compelled to admit, as every one who considers it 

 closely must, I tliink, equally do, that the pha^nomena 

 of tlie human will stand in a very peculiar relation to 

 that question ; and that granting volition to be a cause 

 of action, and granting the QwiuQ freedoui of our will and 

 its complete indepe?uie]ice to choose when a choice of 

 lines of action is brought before us, there is still the 

 question behind What determines the wilH To this 

 question an answer must be found which will leave man 

 a moral and responsible agent. To choose the right 

 and to avoid the wrong, as such, must be left in his 

 power, and a freedom and independence of choice as 

 between these two grand lines of action must be left 



