Valberg's Secondary Qualities

Abstract

In his ingenious paper 'A Theory of Secondary Qualities',1 Eugene Valberg shows himself sympathetic to the spirit, if not the letter, of Locke's views relating to primary and secondary qualities. He holds that it is true that 'colour is not objects' and that 'primary qualities are in objects a way that secondary qualities are not'.2 Locke thought, however, that it was factually true that 'colour is not objects' while Valberg argues that this is a necessary truth. There is, however, a serious gap and some inconsistency Valberg's argument here. Valberg does not begin by arguing straight off that colours do not inhere objects. Rather he merely indicates the usual sort of argument from 'perceptual relativity' and imagines himself talking to someone who had been convinced by it. He asks such a person, 'You say that colour is not objects but only our minds. Let us suppose you are right. Only tell me: what would it be like for colour to be objects?' According to Valberg, however, there is no satisfactory answer to this question. For example, it might be suggested that if colour did inhere objects then a leaf would always look green whether or not one was viewing it under a microscope or, indeed, whatever the conditions of observation were. But, according to Valberg, this would only show that the leaf always looked green but not that the colour green was actually it. Indeed, he concludes that there is no conceivable observation which would provide evidence favour of the hypothesis that colour is objects. Now, Valberg's argument makes use of two assumptions and it is at this point that he uses the first of them, i.e. 'some kind of verifiability principle'. For if there is no conceivable observation which would provide evidence for the hypothesis that colours are objects then this hypothesis is, according to this principle, meaningless.