The limits of rational self interest?

rational

Compulsions aren't "rational."  Compulsions to do harm are most definitely irrational.

to repress his true nature

Ed,
Regarding your post #2, I don't think you can necessarilly say that someone with an unchosen psychological craving for pleasure killing would view a killing as a net-negative value.  Value is determined by the valuer, and while among normal rational people like us it's impossible to see nothing but destruction and negativity in a brutal murder, some sort of psychological value is likely being gained by person comitting the acts.

Question:
Do you agree with the widespread philosophical idea that means alone are chosen by reason, while ends are chosen irrationally?

Rand:
No! I reject the evil idea that choosing ends by reason is impossible. It has destroyed ethics. Everything that I have written is devoted to proving the opposite. Ends are not chosen irrationally. We choose our ends by reason, or we perish. ...

Question:
In an earlier answer to a question, you accuse of context dropping the person who says: "I'm going to cheat my aunt out of her money, and then spend it on a library and devote the rest of my time reading and thinking, which is in my self-interest." What context is he dropping?

Rand:
He is dropping several contexts, primarily that his self-interest is not determined by whatever he feels like doing. To determine one's rational self-interest, one must include all the relevant elements involved in a decision. The first contradiction he would encounter is the idea of robbery. He cannot claim self-interest if he does not grant this right objectively to his aunt. If he decides to follow his own self-interest but to respect nobody else's, he is no longer on an objective moral base, but on a hedonistic, whim-worshipping one. If so, he has disqualified himself; he is claiming a contradiction. If he wants to maintain rationally his own self-interest, and claim he has a case for his right to his self-interest, then he must concede that the ground on which he claims the right to self-interest also applies to every other human being. ...

Question:
Under Objectivism, what would be your social responsibility toward other people?

Rand:
... You would be responsible for any harm you do to other people. ... You would have no right to pass on to others the burden or consequences of your mistakes or failures or whims. In other words, you cannot make other men your victims, and you need not be their victim. ... But it's not good to help someone who is suffering as a result of his own evil. If you help him, you are sanctioning his immorality, which is evil.

Question:
Is it all life or one's own life that one is morally bound to preserve? Suppose a conflict arises between one's own life and happiness, and that of others. What should one do? For instance, should I let the whole nation go down in ruins rather than give up my own life?

Rand:
The moral obligation to maintain one's life does not mean survival at any price. Only one's life is a primary moral obligation--if you want to call it that--because it's the only life over which you have control, the only life you can live, the only life for which ethics gives you guidance. For the same reason that you should value your own life, you should value human life as such. ...

As for the last part of your question: Metaphysically, we are never put in a position where the life of a whole nation depends on the sacrifice of one man. If that occurred (outside of collectivist fiction), we would be living in a different universe, and so the rules of our existence would be different. ...

Question:
Does a person have to be strong (as opposed to weak) to be selfish?

Rand:
No. This is one of the fallacies of today's prevalent morality, altruism, which holds that man must sacrifice himself to others--that service to others is the moral justification of one's life. This creates the idea that it takes a special strength to live by the judgment of your own mind. But, in fact, all it takes is honesty, whatever your level of intelligence or ability. ...

Question:
If an individual thug is stronger than other men, or a national government is stronger than other people, wouldn't reason make them resort to violence?

Rand:
Reason involves knowing the nature and the consequences of your actions, and of knowing where your rational self-interest lies. Reason does not mean you can arbitrarily decide that whatever you want is in your self-interest. Some men do this, but that doesn't mean it's rational. To go by reason is not to be guided by emotions or whims. ...

... Anything man wants or needs must be produced; man must possess knowledge in order to produce it; reason provides that knowledge. Once you know that, if you then decide you don't want to exist by means of reason and production, but by means of muscle instead--since you're physically strong, you prefer to rob or enslave somebody else--you are contradicting the only base on which you could have any justification for your existence. You are guilty of the most irrational contradiction. The only grounds on which you can claim the right to your own life are the same grounds that support the right to life of every human. If you claim an exception or double standard, you cannot defend it by reason.

Moreover, a man of self-esteem does not want the unearned: he doesn't want anything from others that he must obtain by coercion-- by crime or by government force and regulation. ... But no rational person would decide that it's in his self-interest to rob and murder, because he knows that others will and should answer him by the same means.

As for this issue of the level of nations, rationally selfish people do not start wars. Historically, who started them? Woodrow Wilson, a humanitarian reformer, led America into World War One to make the world safer for democracy. Franklin Delano Roosevelt pushed this country into World War Two to save the world and bring everyone the Four Freedoms. In both cases, the state of the world after those wars was infinitely worse than it was before, in precisely those aspects that the humanitarians wanted to correct.

Question:
You say the predominant trend of nineteenth-century intellectuals was collectivist and statist. But didn't Nietzsche advocate individualism? What's your estimate of him?

Rand:
... Nietzsche was a subjectivist and an irrationalist. ... Now there is no greater contradiction than a subjectivist calling himself an individualist. An individualist is a man who thinks independently. A subjectivist is a man who does not care to think--who wants to be guided by feelings and "instincts." To survive, such a man must be a parasite on the thinking of others. An "individualist parasite" is a contradiction in terms.

Question:
Do you oppose young people being concerned with the welfare of others?

Rand:
Taken broadly, yes. ... Every man should be concerned with himself and with his development into the kind of human being fit to live in a society with others.

There are some adult "humans" who lack the capacity for reason and have inhuman appetites.