6 PSTCHOLOOT. 



of related things.* Biit there is no reason to suppose that 

 when different states of mind know different things about 

 the same toothache, they do so by virtue of their all con- 

 taining faintly or vividly the original pain. Quite the re- 

 verse. The by-gone sensation of my gout was painful, as 

 Beid somewhere says ; the thought of the same gout as by- 

 gone is pleasant, and in no respect resembles the earlier 

 mental state. 



Sensations, then, first make us acquainted with innu- 

 merable things, and then are replaced by thoughts which 

 know the same things in altogether other ways. And 

 Locke's main doctrine remains eternally true, however 

 hazy some of his language may have been, that 



" though there be a great number of considei'ations wherein things may 

 be compared one with another, and so a multitude of relations ; yet 

 they all terminate in, and are concerned about, those simple ideas f 

 either of sensation or reflection, which I think to be the whole materials 

 of all our knowledge. . . . The simple ideas we receive from sensation 

 and reflection are the boundaries of our thoughts ; beyond which, the 

 mind whatever efforts it would make, is not able to advance one jot ; nor 

 can it make any discoveries when it would pry into the nature and 

 hidden causes of those ideas." X 



The nature and hidden causes of ideas will never be 

 unravelled till the nexus between the brain and conscious- 

 ness is cleared up. All we can say now is that sensations 

 a^re first things in the way of consciousness. Before con- 

 ceptions can come, sensations must have come ; but before 

 sensations come, no psychic fact need have existed, a nerve- 

 current is enough. If the nerve-current be not given, 

 nothing else will take its place. To quote the good Locke 

 again : 



"It is not in the power of the most exalted wit or enlarged under- 

 standing, by any quickness or variety of thoughts, to invent or frame 



* Yet even writers like Prof. Bain will deny, in the most gratuitous 

 way, that sensations know anything. "It is evident that the lowest or 

 most restricted form of sensation does not contain an element of knowl- 

 edge. The mere state of miud called the sensation of scarlet is not knowl- 

 edge, although a necessary preparation for it. " ' Is not knowledge about 

 scarlet ' is all that Professor Bain can rightfully say. 



f By simple ideas of sensation Locke merely means sensations. 



^ Essay c. H. U., bk. ii. ch, xxiii. § 29 ; ch. xxv. § 9. 



