British Ethical Theorists 0015: Moore's Isolation Test

One of the things that G.E. Moore is noted for is his "isolation test" of intrinsic value.

As Hurka reported in British Ethical Theorists, Moore ultimately defined intrinsic value in terms of what has value in isolation. "By saying that a thing is intrinsically good [our theory] means that it would be a good thing that the thing in question should exist, even if it existed quite alone" (Moore, Ethics, p. 27).

Of course, desirism denies that anything has value "in isolation". Rather, the value of any state of affairs depends on how it stands in relation to one or more desires. However, there is still an argument to be made that Moore's isolation test is helpful in finding out exactly what it is that the agent desires. We have a state of affairs S, and Agent1 finds value in S. This means that Agent1 has a desire that P and P is true in S. It seems as if Moore's isolation test may be a good test for making sure that Agent1's desire is a desire that P and not something else.

The most famous application of Moore's isolation test involved his comparison of two planets.

Let us imagine one world exceedingly beautiful....And then imagine the ugliest world you can possibly conceive. Imagine it simply one heap of filth, containing everything that is most disgusting to us, for whatever reason, and the whole, as far as may be, without one redeeming feature. The only thing we are not entitled to imagine is that any human being ever has or ever, by any possibility, can, live in either, can ever see and enjoy the beauty of the one or hate the foulness of the other.... [S]till, is it irrational to hold that it is better that the beautiful world should exist than the one which is ugly? Would it not be well, in any case, to do what we could to produce it rather than the other? Certainly I cannot help thinking that it would; and I hope that some may agree with me in this extreme instance. G.E. Moore, Principia Ethica.

First, of course, the value of each world depends on how what is true of the world stands in relation to certain desires. We may imagine that the first world is a pristine, safe, and healthy Earth-like world with green meadows, fresh water falling into a clear pool, and healthy animals flittering about or grazing. While we imagine the disgusting world as a huge ball of dung. We encounter an alien species that evolved from a type of dung beetle. They may well agree with us that it is better that a beautiful world exist. However, their idea of beauty is realized in the world that is a big ball of dung. Indeed, they may not be able to imagine a world more beautiful.

This illustrates that the value of the world is determined by how it stands in relationship to desires.

However, we are still left with a question. Do we find value in the beautiful world existing, or is it just the case that our experience of the world is that in which we find value?

This really is the question that Moore was trying to answer. He was responding to Henry Sidgwick's thesis that nothing has value but pleasure. This can be translated in desirism terms to mean that we have only one desire that P, and that is the desire where P = "I am experiencing pleasure". Moore's isolation test is an attempt to prove that this is false. He attempts to do this by asking us to make a choice where, in both cases, "I am experiencing pleasure" is false. Yet, Moore argues, we would choose. In desirism terms, it means that we must have a desire that P that is true in which the beautiful world exists but nobody experiences it. We must have a desire that the beautiful world exist such that we have reason to realize the state of affairs in which "the beautiful world exists" is true.

So, Moore's isolation test may do a poor job of picking out what has intrinsic value. However, it may be useful in picking out more precisely what are the objects of our desires - what states of affairs will actually fulfill our desires.