The Secondary Qualities Analogy

I have so far attacked the moral realist alternative to moral scepticism on several fronts. I have argued against Nagel’s view of reason as capable of moving action by discerning a logically necessary connection between humans and values, between oneself and a conception of being just one amongst many equally real.

It then became worthwhile, in section b) of this chapter, to consider the implications of the normal meaning of moral language and thought. Such a change of focus was worthwhile because I agree that normal ethical meaning and use do rest on moral realist presumptions, although the same language can be used in other ways. But this acknowledgment alone does not save the realist position. It may merely indicate, as the error theory alleges, that most people are mistaken. There is certainly no necessary connection between what people mean when they are evaluating and what is actually, in fact, happening when they are evaluating. If the weight of other evidence points towards the moral sceptic’s world view, the claims of absoluteness, mind-independence and objectivity involved in traditional ways of thinking about and making moral distinctions will not be enough to save the moral realist.

There remain yet other responses open to the moral realist. One such response, quite an attractive one to many and hence requiring further clarification and consideration by the Humean moral sceptic, involves drawing an analogy between moral qualities and so- called secondary qualities like colour and smell. Unlike so-called primary qualities such as squareness, a colour does not exist by itself, ‘out in the fabric of the universe’. Blueness or redness depend on the human mind and exist only in so far as sensibilities are there to perceive them. These secondary qualities supervene on primary qualities and yet are intimately related to the perceiving creature.

But how close is the analogy between secondary qualities like redness and moral qualities like viciousness? The closer the analogy the stronger is the position of the objectivist or realist who wants to say something like:

Moral qualities really do exist just as colours really do exist. It is just that neither is independent of the perceiving human. Of course neither blueness nor wickedness is free from the process of interpretation, shaping and categorising which all data are subject to when entering the human mind. Furthermore the need for training, practice and education applies to perceiving evil properly just as much as to tasting and smelling wine properly. The analogy shows us that moral qualities are real, albeit that they are intimately connected to the sensing human.⁹⁵

If this analogy were a good one Hume’s positive subjectivist case that moral distinctions are a matter of the evaluator having and projecting on to the world certain sentiments would be fatally wounded. Were the analogy a true one that is, there would be a mind-independent element to evaluating just as there is to colour. I hope to show, however, that the analogy is not nearly as strong as it might first appear.

In so far as the importance Hume himself attaches to the analogy with secondary qualities is concerned, Ardal has highlighted the prima facie contrasting positions taken by Hume.⁹⁶ In Book III i 1 Hume supports the analogy:

Vice and virtue, therefore, may be compar’d to sounds, colours, heat, and cold, which, according to modern philosophy, are not qualities in objects, but perceptions in the mind: and this discovery in morals, like that other in physics, is to be regarded as a considerable advancement of the speculative sciences; tho’ like that too, it has little or no influence on practice.

In Book I iv 4 he disparages it:

I assert, that instead of explaining the operations of external objects by its means, we utterly annihilate all these objects, and reduce ourselves to the opinions of the most extravagant scepticism concerning them. If colours, sounds, tastes, and smells be merely perceptions, nothing we can conceive is possest of a real, continu’d, and independent existence; not even motion, extension and solidity, which are the

primary qualities chiefly insisted upon.⁹⁸

If Kemp Smith be right about the order in which Hume wrote the Treatise⁹ then the latter quote is Hume’s more considered opinion. But the two positions may not be as contradictory as they appear. Hume’s attack in Book I is against Berkeleyan idealism, “... the opinion concerning colours, sounds, tastes, smell, heat and cold; which it asserts to be nothing but impressions in the mind.”¹⁰⁰ In other words, Hume attacks the view that secondary qualities (like blueness) are nothing but perceptions in the mind. The eulogy of the analogy with secondary qualities in Book III, on the other hand, can be understood to mean merely that vice and virtue are at least as mind­dependent as colours and tastes.¹⁰¹ At any rate the focus on Hume’s position vis-a-vis the analogy is not too significant for my purposes as Hume is mainly concerned with whether the analogy supports idealism. He wants to decide whether secondary qualities are any less ‘real’ than primary qualities¹⁰² (Book I) and merely makes the comparison with moral qualities (Book III) to show that an element of the subjective is involved. I suspect Hume never contemplated that an objectivist could fasten on to the analogy in the way I have sketched out above. However it is the substance of this claim, that moral qualities are somehow indirectly real in a way similar to secondary qualities like colour, that must be examined.

The issue, in effect, is the extent to which, respectively, moral sentiments and colour perceptions are dependent upon circumstances unrelated to the external world. My position is that moral sentiments are far more person-related, or subjective, than secondary qualities.

Blackbum lists six differences between secondary properties and moral properties.¹⁰³ For example, moral properties supervene on the causal world in a way quite different from the way secondary properties do. And the receptors of secondary properties are well- known, and open to study, whereas the very idea of receptors of moral qualities is highly dubious. And again, evaluative properties are attributive and ‘essentially contested’,^{1 4} unlike secondary ones. So there are significant differences.

I think that the crux of the difference can be captured by comparing the relational properties of both colour and moral distinctions. This manner of looking at the analogy I take from Firth,¹⁰⁵ though the conclusions we draw are not the same. I put the colour-moral difference as follows: To call an object, say grass, green involves two aspects. It is a statement about grass and also about how grass appears to certain types of observers in certain conditions. Grass reflects light of a certain wavelength. This can be called its non-relational property. It is physical and real in a sense (thus ‘really green’)· But in normal lighting conditions for normal people grass also appears in a way which we term green (thus ‘apparently green’). This is its relational property. The grass’s ‘apparent greeness’ depends on people; its ‘real greeness’, its continuing to reflect the same wavelength band, is independent of the observing people. The ‘apparent greeness’ may be unanalysable, or perhaps, more optimistically, analysable only in terms of human psychology and neurophysiology, but the ‘real greeness’ is clearly open to natural science investigation. It is as real as any other external quality¹⁰⁶ (albeit that our interest in ‘real greeness’ is essentially due to grass’s ‘apparent greeness’).

Moral distinctions, let us take wrongness as an instance, seem to me certainly to have the relational property. That is to say, the ‘apparent wrongness’, which depends on people and is in a sense unanalysable (or again analysable only in terms of human psychology or neurophysiology), is analogous to ‘apparent greeness’. Both are subjective. But I find it difficult, nay impossible, to find anything analogous to reflected light waves — any ‘real wrongness’ — that is an external, non-relational quality. ‘Real wrongness’ simply does not exist. Or rather, the external qualities which trigger the ‘apparent wrongness’ reaction are so changing, multitudinous, and complex, and they produce sufficiently varied reactions amongst people,¹⁰⁷ that there can be no coherent non-relational property and no analogy between ‘real greeness’ and some ‘real wrongness’. Whereas secondary qualities do not have the status merely of subjective, mind-dependent perceptions, moral qualities are purely subjective, mind-dependent, related solely to people and their responses. Or, put another way, there really is a ‘tangible’ something that causes ‘greeness’ whereas nothing can be pinpointed which causes ‘wrongness’. Or perhaps better still, ‘what the case is’ is available in the case of secondary qualities but not in the case of moral ones.

Thus the moral objectivists’ attempted analogy between moral qualities and secondary qualities fails. External objects may indeed depend on both their properties and ours but in evaluating there is no analogous, identifiable triggering object external to us. In fact the disanalogy merely strengthens the conclusion that to explain moral evaluation we must focus on people. And if such evaluations be not rational conclusions then we must look to feeling, sentiment and passions, responses that can be projected on to the world and appear to be objectively real.

e)