42 THE AIM AND ACHIEVEMENTS OF SCIENTIFIC METHOD. 



is a rejection of conceptual elements which have their proper 

 home in other Objective contexts. 



In particular this doctrine seems to throw doubt upon the 

 completeness of the distinction between perceptual and con- 

 [ .ceptual space. Conceptual space alone, we are told,* contains 

 points, curves, and surfaces, and is infinitely divisible. These 

 notions are reached as the result of carrying to an ideal limit 

 either suggestions of perception or operations possible only to 

 a certain extent with perceptual material. Upon our view the 

 relation between spatial percepts and concepts should be stated 

 very differently. Our concepts of the relations which we 

 afterwards know as continuous curves and surfaces neither are 

 suggested as ideal limits of perceptual data which are self 

 complete, nor are introduced ab extra to render the data 

 intelligible (as we shall afterwards maintain of the conceptual 

 hypotheses of science) ; they are actual constitutive elements 

 of the percept, and can be thought of apart from the -per- 

 ceptual whole only in the same waj as I may think of the 

 greenness of the apple that I declined yesterday, or the 

 loudness of the cry which disturbed me an hour ago. Again, 

 such a concept as the straight line is not, upon the view here 

 held, gained as the limit of the process represented by the 

 whittling of a stick. On the contrary,' it is the concept of 

 the straight line that gives to the perceptual data the unity 

 which makes them stages of one process. Finally, we may ask 

 whether the process (which Professor James describes) of 

 analysis of a vague given spatial whole into its relational 

 details does not imply in the same way the presence of con- 

 ceptual elements isolated afterwards as the straight ^Mne and 

 point. The fact that jbhe point cannot be perceptually isolated 

 is no reason why it should not have a kind of priority to the 

 perception of areas which makes it in a certain real sense the 

 means by which areas are perceived. The concept is employed, 

 so to speak, in its intension, not in its extension. 



* Pearson, op. cit., p. 203. 



