"We do not represent the image to ourselves, again, without supporting it by a design which resumes its leading features. We do not imagine this design itself without imagining and, in so doing, sketching certain movements which would reproduce it. It is this sketch, and this sketch only, which is represented in the brain. Frame the sketch, there is a margin for the image. Frame the image again, there remains a margin, and a still larger margin, for the thought. The thought is thus relatively free and indeterminate in relation to the activity which conditions it in the brain, for this activity expresses only the motive articulation of the idea, and the articulation may be the same for ideas absolutely different. And yet it is not complete liberty nor absolute indetermination, since any kind of idea, taken at hazard, would not present the articulation desired. "In short, none of the simple concepts furnished us by philosophy could express the relation we seek, but this relation appears with tolerable clearness to result from experiment." The same analysis of facts tells us how the planes of consciousness, of which I spoke just now, are arranged, the law by which they are distributed, and the meaning which attaches to their disposition. Let us neglect the intervening multiples, and look only at the extreme poles of the series. We are inclined to imagine too abrupt a severance between gesture and dream, between action and thought, between body and mind. There are not two plane surfaces, without thickness or transition, placed one above the other on different levels; it is by an imperceptible degradation of increasing depth, and decreasing materiality, that we pass from one term to the other. And the characteristics are continually changing in the course of the transition. Thus our initial problem confronts us again, more acutely than ever: are the forms of number and space equally suitable on all planes of consciousness? Let us consider the most external of these planes of life, and one which is in contact with the outer world, the one which receives directly the impressions of external reality. We live as a rule on the surface of ourselves, in the numerical and spatial dispersion of language and gesture. Our deeper ego is covered as it were with a tough crust, hardened in action: it is a skein of motionless and numerable habits, side by side, and of distinct and solid things, with sharp outlines and mechanical relations. And it is for the representation of the phenomena which occur within this dead rind that space and number are valid.