Note note 33 — ANALYSIS OF THE PHENOMENA OF THE HUMAN MIND James Mill

33 Perhaps the most remarkable case of sensations overlooked on their own account, and considered only as a means of suggesting something else, is the visual, or retinal, magnitude of objects seen by the eye. This is probably the most delicate sensibility within the compass of the mind; and yet we habitually disregard it for all things near us, and use it solely for perceiving real magnitude as estimated by our locomotive and other members. The visual magnitude of a table, or other article in a room, is never thought of for itself; although incessantly fluctuating we never think of the fluctuations; we pass from these to the one constant perception, named the true or real magnitude. It is only for remote objects, as the sun and moon, the clouds, the distant hills, that the retinal magnitude abides with us in its own proper character. In looking down a vista, we may also be aroused to the feeling of retinal magnitude. For perspective drawing, it is necessary that we should arrest the strong tendency to pass from the visible, to the real, forms and dimensions of things.—B.