THE SCOPE OF PSYCHOLOGY. 11 



We need not discuss here whether these writers in draw- 

 ing their conclusion have done justice to all the premises 

 involved in the cases they treat of. We quote their argu- 

 ments only to show how they aj)peal to the principle that 

 no actions hut such as are done for an end, and shoio a choice of 

 means, can he exiled induhitahle expressions of 3Iind. 



I shall then adopt this as the criterion by which to cir- 

 cumscribe the subject-matter of this work so far as action 

 enters into it. Many nervous performances will therefore 

 be unmeutioned, as being purely physiological. Nor will the 

 anatomy of the nervous system and organs of sense be 

 described anew. The reader will find in H. N. Martin's 

 ' Human Body,' in G. T. Ladd's * Phj-siological Psychol- 

 ogy,' and in all the other standard Anatomies and Physi- 

 ologies, a mass of information which we must regard as pre- 

 liminary and take for granted in the present work.* Of 

 the functions of the cerebral hemispheres, however, since 

 they directly subserve consciousness, it will be well to 

 give some little account. 



* Nothing is easier than to familiarize one's self with the mammalian 

 brain. Get a sheep's head, a small saw, chisel, scalpel and forceps (all 

 three can best be had from a surgical-instrument maker), and unravel its 

 parts either by the aid of a human dissecting book,such as Holden's'Manual 

 of Anatomy,' or by the specific directions ad hoc given in such books as 

 Foster and Laifgley's 'Practical Physiology ' (Macmillan) or Morrell's 

 'Comparative Anatomy and Dissection of Mammalia ' (Longmans). 



