Besides the sensation of colour, I have, for one thing, the belief of a certain distance, at which I see {345} the rose; and that of a certain figure, consisting of leaves disposed in a certain form. I believe that I see this distance and form; in other words, perceive it by the eye, as immediately as I perceive the colour. Now this last part of the process has been explained by various philosophers. There is no dispute, or uncertainty, about the matter. All men admit, that this, one of the most remarkable of all cases of belief, is wholly resolvable into association.[98] It is acknowledged, that, by the sense of sight, we receive no sensation but that of a certain modification of light. It is equally proved, that the sensations from which our ideas of distance and figure are derived, are sensations of the muscular actions and touch. How, then, is the Belief generated, that we see extension and figure, as well as colour? After the experience the learner has now had in tracing the rapid combinations of the mind, this presents but little difficulty. He knows, that when we are receiving through the muscles and the touch, the sensations which yield us the idea of extension and figure, we are receiving the sensations of sight at the same time, from the same objects. The sensations of sight, therefore, are {346} associated with the ideas of these tactile and muscular sensations; and associated in the most perfect possible manner; because the conjunction is almost invariable, and of incessant occurrence, during the whole period of life. We are perpetually feeling, and seeing, the same objects, at the same time; so much so, that our lives may be said to consist of those sensations in union; to consist, at least to a far greater degree, of this, than of any one other state of consciousness. [Editor's footnote 98: "All men admit." Certainly not all men; though, at the time when the author wrote, it might be said, with some plausibility, all psychologists. Unfortunately this can no longer be said: Mr. Samuel Bailey has demanded a rehearing of the question, and has pronounced a strong and reasoned opinion on the contrary side; and his example has been followed by several other writers: but without, in my opinion, at all weakening the position which since the publication of Berkeley's Essay on Vision, had been almost unanimously maintained by philosophers.--_Ed._] This intensity of association, we know, produces two effects. One, is to blend the associated feelings so intimately together, that they no longer appear many, but one feeling. The other is, to render the combination inseparable; so that if one of the feelings exist, the others necessarily exist along with it.