A member of the studio audience has sent me some snippets of Peter Railton’s moral theory for my consideration.
It includes this:
"Consider first the notion of someone's subjective interests... For me to take a subjective interest in something is to say that it has a positive valence for me... [But] let us introduce the notion of an [objective] interest, [what someone would want if he knew all the facts]...
I do not have time to investigate Railton’s moral theory in detail. I wish I did, but it would require a sufficiently large gift for me to quit my day job. However, I can present some thoughts on the ideas expressed in this quote.
First, let us recognize the distinction between what a person desires as an end and what a person desires as a means to that end.
Desires-as-ends are not subject to beliefs. There is no difference between what a person desires-as-ends and what that person would desire-as-ends if he knew all of the facts. These would be the same thing.
In this, desires-as-ends are like an agent’s age. There is no sense in talking about a person’s “objective age” as being what the agent’s age would be if she knew all the facts. The person’s age is independent of these types of considerations.
We can, of course, speak of an agent’s “subjective age” as how old she thinks she is – if, for example, there is no record of her birth and nobody alive knew her history. And we can speak of an agent’s “objective age” as the age she would believe herself to be if she knew all the facts. However, we do not need such a convoluted account of “objective age”. There is only one fact that is relevant here – the fact of how old she is.
Similarly, the only facts a person needs to know to determine her objective desires-as-ends are what her desires-as-ends are in fact. No other facts are relevant.
Desires-as-means, on the other hand, are dependent on beliefs. A person can desire a glass of “whatever is in that pitcher over there” because, given her beliefs, she thinks that the contents of the pitcher will quench her thirst. She may be mistaken. The contents of the pitcher might be contaminated in some way. Here, it makes sense to talk about what the agent would desire-as-means if she knew all the facts. In this case, it would not be to drink the contents of that pitcher over there.
Desires-as-means is made up of part desires-as-ends, and part beliefs. Since beliefs can be mistaken, desires-as-means can be mistaken. We can speak of the agent believes would be an effective way of realizing something the agent desires-as-end, and what the agent would claim to be an effective way of realizing a desire-as-end if she knew all of the facts.
Yet, here, too, there is really only one fact that the agent needs to know to make an accurately claim about realizing a desired end. She only needs to know what will bring about a desired end in fact. No other beliefs are relevant.
Here, too, if an agent’s beliefs differ from what is true then she is simply mistaken. Similarly, if her “subjective interests” in Railton’s sense differ from the “interests” she would have if she were fully informed, then those “subjective interests” are merely mistaken. She thinks that the route she has taken will realize what she desires-as-ends, and she is wrong to believe such a thing.
Ultimately, this account simply fails to distinguish properly between desires-as-ends and desires-as-means. Desires-as-means are under the influence of beliefs, and we can distinguish between the means an agent would choose with her current knowledge versus those she would choose if fully informed. This account takes these facts and adds the false claim that desires-as-ends function the same way.
When it comes to desires-as-ends, what objectively fulfills a desire-as-end is a state of affairs in which the proposition that is the object of the desire (as a propositional attitude) is true. That’s it. The agent’s beliefs are irrelevant.
When it comes to desires-as-means, what objectively has value as a means is what will bring about a state of affairs in which the proposition that is the object of the desire-as-ends is true. Again, the agent’s beliefs are irrelevant.
Bringing the agent’s beliefs into either of these concepts merely muddies the water.
Referring to them may provide a useful heuristic for approximating the fact of the matter, but they do not determine what those facts are.