certain manner, but of this arrangement the parts themselves cannot be sensible. To make each part conscious of its relation to all the rest is to suppose an infinite number of intellects instead of one; and to say that a knowledge or perception of each part separately _without_ a reference to the rest can produce a conception of the whole, is a contradiction in terms. Ideas then are the offspring of the understanding, not of the senses. An idea necessarily implies, not only a number of distinct positive impressions, but some bond of union between them, some internal conscious principle to which they are alike communicated, and which grasps, overlooks, and comprehends the whole. The idea of a square, for example, is not the same thing with the compound impression made by the figure on the senses. For the immediate impression of any one of the sides cannot, as a mere sensation, be accompanied with an additional knowledge or reflex image of the remaining three sides, but is a perfectly distinct, physical thing; neither can the actual coexistence of all these impressions be accompanied with a consciousness of their mutual relations to each other, _i.e._ with an idea of the whole, without supposing some general representative faculty, to which these distinct impressions are referred. Otherwise, different impressions made on the same organized or sentient being would no more produce the slightest continuity of thought or idea of the same object than different physical impressions conveyed to different organized beings would produce an immediate consciousness of these different objects or of the relations between them. If to have sensations were the same thing as to compare them, then different persons seeing different objects might without any communication make an exact comparison between them. If to have the sensible impression of the different parts of an object were the same thing as to form an idea of it, then different persons looking at the two halves of any object would be able to compound an idea of the whole between them, though each of them was perfectly unconscious of what was passing in the other’s mind. Unless we suppose some faculty of this sort which opens a direct communication between our perceptions, so that the same thinking principle is at the same time cognisant of different impressions, and of their relations to each other, it seems a thing impossible to conceive how any comparison can take place between different impressions existing at the same time, or between our past and present impressions, or ever to explain what is meant by saying, ‘_I_ perceive such and such objects, _I_ remember such and such events,’ since these different impressions are evidently referred to the same conscious being, which very idea of individuality could never have been so much as conceived of, if there were no other connection between our perceptions, than that which arises from the juxtaposition of the particles of matter on which they are