Science and Morality
Roger Crisp writes…
In his new book The Moral Landscape, Sam Harris claims that science 'reveals' values to us. Kwame Anthony Appiah is one of the many who have pointed out that Harris makes the common mistake of seeking to derive an 'ought' from a series of mere 'is' statements, a mistake pointed out by David Hume centuries ago.
But the relationship between natural science and normative ethics does raise interesting questions. Let's assume that Harris is correct in thinking that the right action is that which maximizes overall well-being, and assume also that well-being consists in the greatest balance of pleasure over pain. Pleasantness and painfulness are properties that scientists — psychologists in particular, but others too — can talk about, and if we assume that these properties can be measured in some way or other, then we find that the property that makes actions right is a property that can be studied by natural science.
But what is the relation between rightness and the property of maximizing well-being? In recent years, several naturalistically inclined philosophers have been inclined towards identifying them. So, just as heat turns out to be the same as molecular kinetic energy, so rightness turns out to be the same as maximizing well-being.
In a book which should be published in the new year, Derek Parfit argues that moral properties and 'natural' properties (the ones studied by science) are far too different to be identified. The claim of the naturalists about rightness in the previous paragraph is, he thinks, rather like the claim that heat is a cabbage.
But there is another option — a broader form of naturalism, to which Parfit is less hostile. This might allow that moral properties and natural properties are indeed different, but insist that moral properties are 'anchored' (to use Robert Audi's term) in natural properties in the same sort of way that mental properties are anchored in physical properties — by supervening on them.
If we continue with our assumption (made just to simplify the argument) that rightness in this world supervenes on the maximization of well-being, it is hard not to think that rightness in all possible worlds will supervene on such maximization. That gives us a necessity claim linking moral and natural properties which those on both sides of the metaphysical debate between naturalism and non-naturalism can agree on. Indeed it may be that there's enough common ground here for that debate to be put to one side, so that we can engage in another genuine philosophical question — how it is that we can understand these necessities. We — those who've understood Hume, anyway — know that it's not through application of the scientific method as that is usually understood. But how, then, do we do it?