THE EXTERNAL WORLD 89 



of relations between perspectives can be rendered con- 

 tinuous, and (if we choose) three-dimensional. 



We can now define the momentary common-sense 

 " thing," as opposed to its momentary appearances. By 

 the similarity of neighbouring perspectives, many objects 

 in the one can be correlated with objects in the other, 

 namely, with the similar objects. Given an object in one 

 perspective, form the system of all the objects correlated 

 with it in all the perspectives ; that system may be 

 identified with the momentary common-sense "thing." 

 Thus an aspect of a " thing is a member of the system 

 of aspects which is the "thing "at that moment. (The 

 correlation of the times of different perspectives raises 

 certain complications, of the kind considered in the theory 

 of relativity ; but we may ignore these at present.) All 

 the aspects of a thing are real, whereas the thing is a 

 mere logical construction. It has, however, the merit of 

 being neutral as between different points of view, and of 

 being visible to more than one person, in the only sense 

 in which it can ever be visible, namely, in the sense that 

 each sees one of its aspects. 



It will be observed that, while each perspective contains 

 its own space, there is only one space in which the 

 perspectives themselves are the elements. There are as 

 many private spaces as there are perspectives ; there are 

 therefore at least as many as there are percipients, and 

 there may be any number of others which have a merely 

 material existence and are not seen by anyone. But there 

 is only one perspective-space, whose elements are single 

 perspectives, each with its own private space. We have 

 now to explain how the private space of a single perspective 

 is correlated with part of the one all-embracing perspective 

 space. 



Perspective space is the system of <c points of view ' 



