Just as man cannot survive by any random means, but must discover and practice the principles which his survival requires, so man's self-interest cannot be determined by blind desires or random whims, but must be discovered and achieved by the guidance of rational principles. This is why the Objectivist ethics is a morality of rational self-interest - or or rational selfishness.
When one speaks of man's right to exist for his own sake, for his own rational self-interest, most people assume automatically that this means his right to sacrifice others. Such an assumption is a confession of their own belief that to injure, enslave, rob or murder others is in man's self-interest - which he must selflessly renounce. The idea that man's self-interest can be served only by a non-sacrificial relationship with others has never occurred to those humanitarian apostles of unselfishness, who proclaim their desire to achieve the brotherhood of men. And it will not occur to them, or to anyone, so long as the concept "rational" is omitted from the context of "values," "desires," "self-interest" and "ethics."
The term "interests" is a wide abstraction that covers the entire field of ethics.
It includes the issue of:
- Man's values,
- His desires,
- His goals
- And their actual achievement in reality.
A man's "interests" depend on
- The kind of goals he chooses to pursue,
- His choice of goals depends on his desires,
- His desires depend on his values -
- And, for a rational man, his values depend on the judgment of his mind.
Desires (or feelings or emotions or wishes or whims) are not tools of cognition; they are not a valid standard of value, nor a valid criterion of man's interests. The mere fact that a man desires something does not constitute a proof that the object of his desire is good, nor that its achievement is actually to his interest.
~ Found at Ayn Rand Lexicon - Self-Interest