  Subsequent discussion has shown that the relationship between supervenience and reduction is a complicated matter, and though I think that Moore's position is defensible this is not the place to take the issue further. Instead I want to turn to the concept of intrinsic value which is central to Moore's theory. One aspect of this is easy, namely the distinction between the ‘intrinsic’ value of a situation and its ‘instrumental’ value: this is the distinction between the value inherent in a situation and that which depends only on the situation's consequences. Despite this distinction it remains the case that intrinsic value is the fundamental type of ethical value, since instrumental value is definable in terms of the intrinsic value of a situation's consequences. But intrinsic value is not merely non-instrumental value; for it is also to be distinguished from what Moore calls the ‘value as a part’ of a situation, namely the extra contribution which the situation makes to the value of a complex situation of which it is a ‘part’, over and above its intrinsic value. This is not a conception which is familiar to us, but Moore illustrates the point by the following case: although knowledge has little intrinsic value, the value of the aesthetic appreciation of a beautiful work of art (which is, according to Moore, potentially one of the most valuable things there is) is greatly enhanced by knowledge about it. So this kind of knowledge can have a substantial ‘value as a part’ even though it has little intrinsic value. As before intrinsic value remains the fundamental conception of value, since a situation's value as a part is defined in terms of the overall intrinsic value of a complex situation to which it makes a contribution beyond its own intrinsic value. Nonetheless this point implies that a thing's intrinsic value is not simply its value irrespective of its consequences; it is also its value irrespective of its context. Hence the concept of intrinsic value is to be such that a type of situation has the same intrinsic value in all contexts — which is why Moore holds that its intrinsic value depends only on its ‘intrinsic nature’.