... another number, so in the field of space the relations are facts of the same order with the facts they relate. If these latter be catches in the circle of vision, the former are certain other ... patches between them. When we speak of the relation of direction of two points toward each other, we mean simply the sensation of the line that joins the two points together. The line is the relation; ... when we compare the palm with the back of the hand, the nape of the neck with its anterior surface, the breast with the back; in short, any two distant parts of the skin with each other. and moreover,...