This may be an interesting read: Good and Obligation.

In what goes below I shall argue against the doctrine that there are moral obligations (in any unconditional sense), but at the same time I will affirm the objectivity of good. My general procedure will be, first, to argue that the doctrine of moral obligations is both a dubious doctrine and a superfluous doctrine and, second, to suggest that it is fallacious to assume – as might be tempting – that a belief in the objectivity of good commits one to a belief in moral obligations, or that a denial of moral obligations is incompatible with a belief in the objectivity of good.

I don't have access to the full paper, but I'll look to see if I can find it (for free) somewhere. I can see the appeal of the view, especially as I'm partial to Anscombe's remarks that the term "ought" lacks any real meaning but also do not agree with the moral nihilist who cannot draw a moral distinction between charity and genocide.

As a particular example, an ethical naturalist could claim that being good is a natural property without claiming that obligations are a natural property/phenomena.

And presumably my obligations, if such things exist, concern me, whereas the ethical goodness of charity has nothing (directly) to do with me at all.

I have found it Michael, but how can I attach it here? I did not read it yet, but seems fun to get into!

Do you have this upload icon next to the floppy disk/save icon? It might be for mods/sponsors only?

Nope... Perhaps I can try via PM... hmm, alas... Well, there is nothing left to do then but make me a mod methinks ;) Nahh, but let me know if there is another way I can get it to you. I can access it but probably due to my uni having a subscription.

@Tobias

So the summary of the argument of that paper is:

I am convinced that it is sheer effrontery to believe that anyone is morally obligated to do that which will make him unhappy. And yet I am just as fully convinced of the objectivity of good, that is, that some things are better than others, independently of what anyone happens to desire and independently of what any particular person happens to find to be satisfying, and that the uniqueness and dignity of man can never be understood in the absence of this concept. Why cannot both of these convictions be maintained? Surely the burden of proof rests in showing that they are not compatible.

In other words, for some X it is conceivable that:

1. "X is good" is true
2. "You ought do X even if doing so makes you unhappy" is false

I don't suspect you find this argument particularly compelling. I probably wouldn't if I were committed to your position. I'd simply reject (2).

There is, however, a passage that might provide a good launchpad for further discussion:

It would appear, indeed, that people who conceive of good in an objectivistic and non-naturalistic way, who believe, for example, that there is such a thing as a better character and such a thing as a better way of treating others, would be particularly inclined to believe that there are in fact moral obligations.

The focus is on ethical non-naturalism. But what of ethical naturalism? Is the person who claims that goodness is a natural (i.e. empirical) property committed to the claim that obligations are a natural (i.e. empirical) phenomena? Can science determine the physical existence of moral obligations? It seems like an absurd notion. But is ethical naturalism absurd? If not then there must be a conceptual (and so semantic) distinction between something being good and someone having an obligation.

The theist here would argue: because it is an action warranted by God. At the least, the word 'ought' or 'should' suggests a verdict, and thus mandates a lawgiver.

The divine law being mandated by God makes it righteous and thus 'good.' So really, you ought to do good because it is..... good. And since good is derived from God, you are basically pointing to a primal reason. Without this precedence, doing good sometimes becomes arbitrary (as some atheists claim such a position).