I am responding to some comments that Chris wrote in an earlier post, drawing a comparison and a contrast between his statements and mine.
Doing X is beneficial only in so far as makes it more likely that I can achieve some state Y and it is a fact that I do desire Y and it does not excessively keep me from achieving some other state Z that I also desire.
I would put it this way.
I have a 'reason for action' to do X if and only if I have a desire that P and either P is true of doing X or P is true of some state S where doing X results in S.
If I also have a desire that Q, and doing X will make Q false, or doing X will create a state T and Q is false in T, then I also have a reason not to do X.
From these, a person practical-ought to do X if and only if the number and strength of the desires fulfilled by doing X is greater than the number and strength of the desires that exist for not doing X.
I think that this captures everything in Chris' statement. But why stop here? The mistake is not in the fact that this description is mistaken - it isn't. The mistake is in thinking that this description is complete.
We can go a lot further - far enough to get into the realm of an objective interpersonal morality from these beginnings.
Note that there is often a difference between what a person has a reason to do and what he believes he has a reason to do. A person can believe that he has a reason to do X (e.g., he has a desire to please God and believes that doing X will please God), and yet the statement that he has a reason to do X is false (because the statement 'X will please God' is false).
Now, I also want to introduce a distinction between the statements, "I have a reason to do X" and "There are reasons for me to do X."
Certainly, the reasons that I have are not the only reasons that exist. The desires that other people have are reasons for action that exist. However, these are reasons for action that they have, not reasons for action that I have.
While it is true that only a minute portion of reasons for action that exist are reasons for action that I have, it would be foolish of me to ignore the reasons for action that exist. That is to say, I do have reasons for action to take into consideration the reasons for action that other people have. This is relevant both in causing them to act in ways that would fulfill my desires, and to refrain from acting in ways that would thwart my desires.
Not only do I have reason to note what those reasons are, I also have reason to change their reasons for action to the degree that it is in my power to do so.
If I create or strengthen in others a desire that P, then I give them a stronger reason to act so as to realize a state in which P is true. This, in turn, would help to fulfill my own desire that P.
Furthermore, if a desire that Q gives people a reason to act in ways that will prevent P from being true, then I have reason to prevent people from acquiring a desire that Q, to the degree that it is within my power to do so.
The same is true of others. They, too, have reason to promote those desires that tend to fulfill other desires and inhibit those desires that tend to thwart other desires, to the degree that they have the desires at risk of being promoted or thwarted.
Applying this to a whole population, we can identify desires that people generally have the most and strongest reason to promote and desires that people generally have the most and strongest reason to inhibit.
Plus, we can talk about those desires, and discover where gaps are to be found between the desires that people generally think they have many and strong reasons to promote or inhibit, and those desires that people generally as a matter of fact have the most and strongest reasons to promote or inhibit.
Here, I find an analogy to location is useful. Limiting the term 'benefit' to relationships between objects of evaluation and the speaker is as absurd as limiting the use of location terms to relationships between objects and the speaker.
Certainly, everything in the universe has a location relative to me. But they also have a location relative to each other. I can talk about the relationship between the motion of the earth and me. However, I can also talk about the relationship between the motion of the earth relative to the sun, or relative to Venus, or relative to the motion of the earth at some point in the past or the future.
Similarly, I can make true statements about the relationship between states of affairs and my own desires. However, I can also talk meaningfully about relationships between states of affairs and other desires that exist. I can speak meaningfully about relationships between malleable desires and other desires, and about desires that people generally have many and strong reasons to promote or to inhibit.
In exactly the same way that location claims remain perfectly objective scientifically-verifiable claims in spite of the fact that different claims (including claims relative to the position of the author) are possible, value claims also remain perfectly objective.
There is nothing in anything that I have written that requires taking even the slightest step outside of the realm of objective science.
Consequently, Chris' original statement does not prove or even successfully assert that there is a subjective morality outside of the realm of objective science. It is a subset of what is true of objective morality. It falsely claims a distinction where no distinction can be found in fact.