Page:Ferrier's Works Volume 3 "Philosophical Remains" (1883 ed.).djvu/374

364 another sense, could he converted into that perception. We agree with Mr Bailey in thinking that no process of association could effect this conversion; that if we did not originally see colours to be out of each other, and the points of the same colour to be out of each other, we could never so see them; and that his argument, when thus based on the negation of all original visual extension, and on the supposition that the touch is the sole organ of every species of externality, would remain invulnerable.

But, with the admission of the visual intuition of space, the objection vanishes, and the argument is shorn of all its strength. This admission relieves the theory from the necessity of maintaining that conceptions derived from touch are transmuted into the perceptions of sight. It attributes to the sight all that ever truly belongs to it—namely, the perception of colours out of one another; it provides the visual intuitions with an externality of their own, and the theory never demands that they should acquire any other; and it leaves to these visual in tuitions the office of merely suggesting to the mind tactual impressions, with which they have been in variably associated in place. We say in place; and it will be found that there is no contradiction in our saying so when we shall have shown that it is the touch, and not the sight, which establishes a protensive interval between the organ and the sensations of vision.

Visible extension, then, or the perception of colours