12 PEOF. W. JAMES :

grasped by a single look. The relative positions of the shops in a town, separated by many tortuous streets, have to be thus constructed from data apprehended in succession, and the result is a greater or less degree of vagueness. That a sensation be discriminated as a part from out larger enveloping space is then the conditio sine qua non of its being apprehended in a definite spatial order. The problem of ordering our feelings in space is then, in the first instance, a problem of discrimination, but not of discrimination pure and simple ; for then not only coexistent sights but coex- istent sounds would necessarily assume such order, which they notoriously do not. Whatever is discriminated will appear as a small space within a larger space, it is true, but this is but the very rudiment of order. For the location of it within that space to become precise, other conditions still must supervene ; and the best way to study what they are will be to pause for a little and analyse what the expression " spatial order " means. 2. Space-relations. Spatial order is an abstract term. The concrete percep- tions which it covers are figures, directions, positions, mag- nitudes and distances. To single out any one of these things from a total vastness is partially to introduce order into the vastness. To subdivide the vastness into a multi- tude of these things is to apprehend it in a completely orderly way. Now what are these things severally ? To begin with, no one can for an instant hesitate to say that some of them are qualities of sensation, just as the total vastness is in which they lie. Take figure : a square, a circle and a triangle appear in the first instance to the eye simply as three different kinds of impressions, each so pecu- liar that we should recognise it if it were to return. When Nunnely's patient had his cataracts removed, and a cube and a sphere were presented to his notice, he could at once perceive a difference in their shapes ; and though he could not say which was the cube and which the sphere, he saw they were not of the same figure. So of lines : if we can notice lines at all in our field of vision, it is inconceivable that a vertical one should not affect us differently from an horizontal one, and should not be recognised as affecting us similarly when presented again, although we might not yet know the name * vertical,' or any of its connotations, beyond this peculiar affection of our sensibility. So of angles : an obtuse one affects our feeling immediately in a different way