136 PSYCIIOLOOY. 



jiature that there is no chaiK-e of his ever forgetting it or failing to 

 .saturate with it all his meditations, the student of psychology has next 

 to appreciate tlie association between these two orders of phenomena. 

 . . . They are associated in a manner so intimate that some of the 

 ■greatest thinkers consider them diflferent aspects of the same process. 

 . . . When the rearrangement of molecules takes place in the higher 

 regions of the brain, a change of consciousness simultaneously occurs. 

 . . . The change of consciousness never takes place without the change 

 in the brain ; the change in the brain never . . . without the change 

 in consciousness. But tvliy the two occur together, or what the link is 

 which connects them, we do not know, and most authorities Vjelievo 

 that we never shall and never can know. Having firmly and tena- 

 ciously grasped these two notions, of the absolute se[)aratcness of mind 

 and matter, and of the invariable concomitance of a mental change 

 with a bodily change, the student will enter on the study of psychology 

 with half his difficulties surmounted." * 



Half his difficulties ignored, I sliould prefer to say. For 

 this ' concoiiiitance ' in the midst of ' absolute separateuess ' 

 is an utterly irrational notion. It is to my mind quite in- 

 conceivable that consciousness should have nothing to do 

 with a business which it so faithfully attends. And the 

 'question, 'What has it to do?' is one which psychology 

 has no right to ' surmount,' for it is her plain duty to con- 

 sider it. The fact is that the whole question of interaction 

 and influence between things is a metaphysical question, 

 -and cannot be discussed at all by those who are unwilling 

 i;o go into matters thoroughly. It is truly enough hard to 

 imagine the ' idea of a beefsteak binding tAvo molecules 

 together ; ' but since Hume's time it has been equally hard 

 to imagine anything binding them together. The whole 

 notion of ' binding ' is a mystery, the first step towards the 

 solution of which is to clear scholastic rubbish out of the 

 way. Popular science talks of * forces,' ' attractions ' or 

 * affinities ' as binding the molecules ; but clear science, 

 though she may use such words to abbreviate discourse, has 

 no use for the conceptions, and is satisfied when she can 

 express in simple ' laws ' the bare space-relations of the 

 molecules as functions of each other and of time. To the 

 more curiously inquiring mind, however, this simplified 

 expression of the bare facts is not enough ; there must 



* Op. cit. p. 11. 



