PREFACE ix 



of the education of old feculties to new heights, and 

 of the discovery of new faculties altogether — ^all this 

 is no Utopian silliness, but is bound to come about 

 if science continues her current progress. 



Take but one example. In the first half of last 

 century, hypnotism, or mesmerism as it was then 

 called, was in complete scientific disrepute. To-day, 

 all the main claims of its founders have been verified, 

 and many new facts unearthed. Every text-book 

 on the subject will tell you that men may be made 

 insensible to pain by hypnosis alone without any drug, 

 many women even being delivered of children under 

 its influence without suffering. Temperature can 

 be changed, blisters raised, and many other processes 

 not normally under the control of the will can similarly 

 be affected. The mind can be raised to an abnormal 

 sensitiveness, in which differences between objects 

 that are completely unrecognizable in ordinary waking 

 existence, such as those between the backs of two 

 cards in a pack, may be easily distinguished. 



If such possibilities are open to the empiricism 

 of the hypnotist, what may we not await from any 

 truly scientific knowledge of mind, comparable even 

 in low degree to our knowledge of, say, electricity ? 



But these in a sense are all details, relevant in a 

 way, and yet only details. There is something still 

 more fundamental in the biologist's attitude. He 



