What is meant by "intrinsically desirable"? To say that something is intrinsically desirable is to say that it is desirable, taken just for itself, viewed abstractly, and in particular, viewed without respect to any consequences its existence will or may produce. For instance, we should not say that having an appendectomy is intrinsically desirable. Doubtless having one is a good thing, if one has appendicitis. But it is desirable, not just for itself, but because of its consequences, in the preservation of the patient's life and avoidance of pain. Or, owning a hi-fi set is hardly intrinsically desirable. The point of owning such a set lies in its consequences: the production of sounds more similar to actual musical performances.
We can put this in another way. If anything is desirable, it is so because of the kind of thing it is, because of the properties it has or relations within which it stands. Now, some of the properties that make a thing desirable do not involve anything beyond the thing or event or state of affairs said to be desirable; they are what they are independently of the remainder of the world, in the sense that it would be logically possible for the rest of the world to be different, but for them to remain the same. (The property of causing some future event is not one of these.) Such properties we can call intrinsic, and we can say that something—an event, state of affairs, or thing—is intrinsically desirable if it is desirable in view of its intrinsic properties alone.
The term "instrumentally desirable" contrasts with "intrinsically desirable." To be instrumentally desirable is to be desirable on account of actual or expectable effects; so that an appendectomy is instrumentally desirable in view of what it will bring about. Presumably, something is instrumentally desirable only because the expected results, immediate or remote, are intrinsically desirable.
Something can be both intrinsically and instrumentally desirable at once. Consider a child who is swinging, in a rapturous state of enjoyment. We shall probably think that being in this state of mind (and perhaps body) is worthwhile for itself alone. To be in a state of rapturous enjoyment of the experience of swinging is for one's state of mind to have an intrinsic property, on account of which the child's experience is desirable. So we shall say that the child's experience is of intrinsic worth. But his experience is perhaps instrumentally desirable as well, for it may help to make him a more relaxed, better-adjusted person in the future.
(Richard B. Brandt, Ethical Theory: The Problems of Normative and Critical Ethics, Prentice-Hall Philosophy Series, ed. Arthur E. Murphy [Englewood Cliffs, NJ: Prentice-Hall, 1959], 302-3 [italics in original])
