ON THE PSYCHO-PHYSICAL VIEW OF NATURE. 473 



ticians, 1 as Hobbes had been before him, Berkeley had a 

 clear conception of the following definite problem : By 

 what succession of physical and mental experiences, by 

 what " organic and vital data," do we become aware of 

 space and of body or matter ? His answer, which makes 

 tactile sensations the base, has been advocated and quoted 

 by English psychologists of the Association school up to 

 the present day, and forms the text for their various 

 explanations. 



The genesis of space perception was much discussed 

 in the circle of Locke's friends, Molyneux proposing 

 the celebrated query 2 named after him, and Cheselden 

 describing at length, in the Philosophical Transactions, 

 the experiences of an adult blind patient who had 

 received his sight by couching. The eighteenth century 

 brought other isolated researches of an experimental or 

 mathematical nature, which may be regarded as the 

 beginnings of an exact treatment of the relation of psy- 



ing each particular phenomenon to 

 general rules, or showing how it 

 follows from them. We should 

 propose to ourselves nobler views, 

 such as to recreate and exalt 

 the mind," &c. In the following 

 paragraph Berkeley refers to the 

 ' Principia ' as "the best grammar 

 of the kind " he was speaking of. 



1 A very full account of this con- 

 troversy will be found in a paper 

 by Prof. Geo. A. Gibson in the 

 ' Proceedings of the Edin. Math. 

 Soc.,' vol. xvii. 



2 The query i.s given in Locke's 

 ' Essay,' Book II. ch. ix. 8, as 

 follows : " Suppose a man born 

 blind, and now adult, and taught 

 by his touch to distinguish be- 

 tween a cube and a sphere of the 

 same metal and nighly of the same 

 bigness, so as tg tell when he felt 



one and the other, which is the 

 cube and which the sphere. Sup- 

 pose, then, the cube and sphere 

 placed on a table, and the blind 

 man made to see : Query, whether 

 by his sight, before he touched 

 them, he could now distinguish, 

 and tell, which is the globe, which 

 is the cube ? To which the acute 

 and judicious proposer answers, 

 No." For a full analysis of actual 

 cases, such as that of Cheselden, 

 and more recent ones, see Wundt, 

 ' Physiologische Psychologic,' vol. 

 ii. p. 233. That Berkeley was, 

 however, neither a psycho-physicist 

 nor a physiological psychologist in 

 the modern sense, is well remarked 

 by Campbell Fraser in his essay 

 on Berkeley (Blackwood's " Philos. 

 Classics," ' Berkeley,' p. 45, &c.) 



