a certain element of whereness (so to speak) as an essential part of it. Yet to the question, Where, then, is it? one may be unable to give any sharp answer, which will be able to name exact boundaries. Here one deals, of course, with an experience which bears, perhaps, a very loose relation to its own physical cause. Recent discussions of space theories in psychology have brought into prominence these primitive and undifferentiated space experiences, very obvious in the inner life, but not at all capable of being made to answer the sharp questions as to Where? and How large? and How bounded?—questions which we ask with a priori assurance and merciless rigidity concerning whatever pretends to be an external thing in space. The bodily disorder that causes the vague pain aforesaid, must, indeed, have a definite, if inaccessible, spatial character. The pain itself is spatial, but indefinite. One can perfectly well experience, moreover, a blur in the field of vision,—a blur due to the conditions of a nervous headache,—and yet one may be as sure that this blur has for him a size and shape, as he is wholly unable, subjectively, to define just what this size and shape may be. With the perimeter one might, indeed, discover the definite size and shape of the defect in the objective field of vision. None the less would the blur itself, as seen, remain vague. But since internal phenomena have, indeed, their essence in being perceived, one must then say of such experiences that really indefinable shapes, essentially indefinite sizes and places, have nothing contradictory about them, so far as our inner experience goes, since we constantly experience just such internal things. Why, then, do we so rigidly insist a priori that what is thus a common-place experience in the inner world, does not and cannot hold for the outer world and for the external things? I answer, the principle of spatial definiteness holds for external things only because definite localization is a conditio sine qua non of any appeal to another to verify the experiences that we ourselves have. But by an external thing we mean an object of experience which is, or may be, a common object for as many observers as you please. An object, however, can be
