Note 28 — Chapter IV

This consideration disposes of the view that, if colour is relative to perception, the primary qualities, as being inseparable from colour, must also be relative to perception; for it implies that the primary qualities cannot from their very nature be relative to perception. Moreover, if the possibility of the separation of the primary qualities from colour is still doubted, it is only necessary to appeal to the blind man's ability to apprehend the primary qualities, though he may not even know what the word 'colour' means. Of course, it must be admitted that some sensuous elements are involved in the apprehension of the primary qualities, but the case of the blind man shows that these may relate to sight instead of to touch. Moreover, it, of course, does not follow from the fact that sensuous elements are inseparable from our perception of bodies that they belong to, and are therefore inseparable from, the bodies perceived.