270 PSTCHOLOGT. 



HISTORICAL. 



Let us now close with a brief historical survey. The 

 first achievement of note in the study of space-perception 

 was Berkeley's theory of vision. This undertook to establish 

 two points, first that distance was not a visual but a tactile 

 form of consciousness, suggested by visual signs ; secondly, 

 that there is no one quality or ' idea ' common to the sensa- 

 tions of touch and sight, such that prior to experience one 

 might possibly anticipate from the look of an object any- 

 thing about its felt size, shape, or position, or from the 

 touch of it anything about its look. 



In other words, that primitively chaotic or semi-chaotic 

 condition of our various sense-spaces which we have 

 demonstrated, was established for good by Berkeley ; and 

 he bequeathed to psychology the problem of describing the 

 manner in which the deliverances are harmonized so as all 

 to refer to one and the same extended world. 



His disciples in Great Britain have solved this problem 

 after Berkeley's own fashion, and to a great extent as we 

 have done ourselves, by the ideas of the various senses sug- 

 gesting each other in consequence of Association. But, either 

 because they were intoxicated with the principle of associa- 

 tion, or because in the number of details they lost their 

 general bearings, they have forgotten, as a rule, to state under 

 tvhat sensible form the primitive spatial experiences are found 

 which later became associated with so many other sensible 

 signs. Heedless of their master Locke's precept, that the 

 mind can frame unto itself no one new simple idea, they 

 seem for the most part to be trying to explain the extensive 

 quality itself, account for it, and evolve it, by the mere asso- 

 ciation together of feelings which originally possessed it not. 

 They first evaporate the nature of extension by making it 

 tantamount to mere ' coexistence,' and then they explain 

 .coexistence as being the same thing as succession, provided it 



subject. It is a real optical sensation, seeming introspectively to have 

 notliing to do "with locomotor or other suggestions. It is easy to say that 

 'the Intellect produces it,' but what does that mean? The investigator 

 who will throw light on this one point will probably clear up other diffi- 

 culties as well. 



