[Serious] An Argument For Ethical Egoism

[The Grand Nudger]

I, personally, would improve the argument, rather than argue against what appears to be broad dissatisfaction from every corner for a wide variety of reasons.

Meanwhilke, this -

It does establish it because if moral realism is true then we, morally speaking, ought to do something.

If we only ought to do what we can do, and psychological egoism is true, then it is true that the only thing that we ought to do is act in our own self-interest. That's ethical egoism.

Is not moral realism or ethical egoism. The truth of ethical egoism does not depend on whether psychological egoism is true, or on our ability to do this that or the other thing, or even the coherence between what can be done and what self interest demands. You're angling more for rational egoism. Under ethical egoism, whatever it is that self interest dictates, regardless of whether or not it is rational and whether or not you can do it, is "good".

If you want to go to the game, then you should, regardless of whether or not you have a ticket, regardless of whether or not there are any seats left open. If there's one seat, and two people who want to go to the game, then they both should™, despite the fact that only one -can-. Your argument doesn't allow for that even though ethical egoism does. Nor does your argument allow for the fact that doing what you want but can't is one way of maximizing self interest. Self interest is the focus of ethical egoism, not the completion of some action x...and self interest doesn't have to be rational or even a statement of some plausible end state.

I wanna be a princess.

Still, the removal of the troubling issue of premise one would be an improvement, if for no other reason but because, as you mention, something being a true normative statement but also pure lulz (like, say, the normative demands that we bang our heads against walls or sprout wings and fly or that I should be a princess) is -still- a true normative statement with respect to what it purports to report. Realism contends that these statements are objective, but egoism, in any form, is explicitly subjective. You don't need it to get where you're going, anyway. It would also reduce my ability to accept every premise and then argue that the conclusion is false by reference to how well it sits in a natural realist context.

Ultimately, though, I don't think that you're going to have much success with trying to leverage a descriptive position on morality to establish or imply a meta-ethical position. When the argument is scrubbed for issues of structure, people will still point out that the assertions may not be (or certainly aren't) true. I mention this from a position of some experience on the boards, lol.

ala

Descriptive natural realism is true.
Ought implies can
Therefore natural realism is true.