April 19, 1895.] 



SCIENCE. 



427 



on inside of you as you listen to me — I 

 should speak technically of analyzing your 

 consciousness. Consciousness is the mind 

 at any moment. Mind, therefore, is the 

 sum-total of consciousnesses experienced in 

 the lifetime of the individual. You have 

 one mind, extending (I hope) over seven tj' 

 full years ; but the mind upon which you 

 experiment at any given moment for j)sy- 

 chological purposes — or the mind which j'ou 

 make up at a given moment — is called j-our 

 consciousness. So that psychology, while 

 it is the science of mind, in the sense that 

 it deals with all the mental experiences of 

 a man, from the time of his birth to the 

 time of his death, deals in any special hour, 

 during any special enquiry, with the phe- 

 nomena of consciou.sness. 



But consciousness — as the number of 

 words in my catalogue of a moment ago 

 sufliciently indicated — is a very intricate, 

 complex and tangled matter. If we are to 

 examine it at all carefully, we must try, first 

 of all, to get some sort of order into its phe- 

 nomena. Let us begin the attempt at once 

 of describing our internal experiences, as 

 accurately as possible. 



We notice, at the outset, that we are to a 

 large extent at the mercj' of our surround- 

 ings, of things outside of us. We are not 

 free to see what we like, to hear what we 

 like, to touch what we like; what we see 

 and hear and touch is all determined for us, 

 by the physical nature of the bodies from 

 which impressions come. You can under- 

 stand, of course, that tliis is true in the 

 simple instances that I have given ; but I 

 want to prove to you that it is true of a 

 very large part, indeed, of our mental ex- 

 perience. Put down in the first place (1) 

 sensations and perceptions. Every time 

 that one of our sense-organs is excited, is 

 put in action, that is done by means of 

 something in the external world. An 

 ether-vibration makes us see ; an air-vibra- 

 tion makes us hear or smell, and so on. 



Those are sensations. And perceptions 

 only differ from sensations in being more 

 complicated. Thus in the sphere of sight, 

 you perceive a house or a tree ; in the sphere 

 of hearing you perceive a musical harmony 

 or a musical discord ; in the sphere of touch 

 you perceive that a complex of impressions 

 is a piece of wood, or a piece of wire, or 

 what not. The tree and the house are com- 

 pound impressions, containing many colors 

 and manj- shapes ; the musical chord is a 

 compound of three or four or more simple 

 tones, and so on. All this, very obviously, 

 comes from the outside world. So, too, 

 does (2) memorj-. You cannot remember 

 what has not happened. If you try to re- 

 member a name, you try to recover a lost 

 perception — the ijerception of the spoken 

 word. If you try to remember a picture, 

 you are attempting to recover a lost visual 

 perception. It is for this reason that the 

 psychologist distinguishes kinds or types of 

 memorj' — the visual, the auditor}' and the 

 motor. People who can play chess blind- 

 fold have the visual memory verj' highly 

 developed. They do not, perhaps, see every 

 piece in their mind's eye, but they see the 

 board as a whole, and know where each 

 piece upon it is. Most ' extemi)ore ' speak- 

 ers, too, rely upon their visual memory. 

 There is comparatively little true extempore 

 speaking done. Of course, if a man is 

 thoroughly familiar with his subject, or is 

 speaking under the influence of strong em- 

 otion, he may be able to address an audi- 

 ence without preparation. But most of us 

 who speak ' without notes ' do so by the 

 aid of our visual memory ; we see what we 

 have written, mentally, paragraph by para- 

 graph, and when our eyes are on our hear- 

 ers, are really reading from a memory 

 manuscript. Instances of good auditory 

 memory, again, are furnished by those fortu- 

 nate persons wlio can recall accurately the 

 airs of an opera that they have only once 

 heard. And people who play the piano 



