Why did Ayn Rand consider rational selfishness a virtue?

Ayn Rand, the American author of The Fountainhead and Atlas Shrugged, grounded her philosophy of Objectivism in a teleological view of human life. She argued that because all living organisms act to preserve their own existence, life itself is the ultimate value and the standard by which all actions are evaluated.1

For Rand, "rational selfishness" is considered a virtue because it represents the pursuit of one’s own life as a rational being. She defined a virtue as the act by which one gains or keeps a value, and since reason is humanity's primary means of survival, she identified rationality as the highest human virtue. Consequently, acting in one's own self-interest—defined as the pursuit of one's own happiness—is a moral necessity for a rational individual.1

Conversely, Rand viewed altruism—which she characterized as placing the interests of others above one's own—as a fundamental vice, as it requires the negation of the individual's own life and rational values.1