Rand and Friedman were both champions of free markets, but they approached capitalism from opposite directions. Friedman argued from freedom and economic efficiency—capitalism works better and preserves liberty. Rand argued from morality and human nature—capitalism is the only system consistent with man's rational, productive nature. Friedman was a pragmatist willing to accept piecemeal reforms; Rand was an absolutist who rejected compromise as sanctioning evil. She believed Friedman's amoral defense undermined capitalism by conceding its opponents' moral premises. For Rand, the question was not what works but what is right.

Rand's 'selfishness' is not the predatory, disregard-for-others behavior most people associate with the word. She defined it as rational self-interest: pursuing one's own life, values, and happiness without sacrificing oneself to others or others to oneself. In her ethics, the 'selfish' person is the producer, the creator, the independent thinker who trades value for value. The 'unselfish' person who gives up their own happiness for others is, in her view, morally compromised. Critics argue this conflates self-interest with selfishness, but Rand's point was precisely to reclaim the word as a badge of honor for individualists.

Rand was deeply influential on the libertarian movement but rejected the label outright, calling libertarians 'hippies of the right.' Her objection was philosophical, not personal. Libertarianism, as she saw it, was a political position detached from any coherent moral foundation—it demanded liberty without explaining why liberty is right. Moreover, many libertarians embraced anarchism, which Rand considered incompatible with capitalism and with human life, since a just society requires a government with a monopoly on retaliatory force. She insisted that Objectivism is an integrated system in which politics is a consequence of ethics, not a standalone doctrine.

Atlas Shrugged (1957) is the fullest literary expression of Objectivism—Rand wrote it expressly to embody her philosophy in dramatic form. Its plot follows the mysterious disappearance of the world's productive individuals—industrialists, inventors, thinkers—who go on strike against a society that exploits and demonizes them. The novel dramatizes her core ethical claim: the producers are the true benefactors of humanity, and the morality of sacrifice is the weapon of those who wish to live off their achievements. Rand later said that in writing it she had to define Objectivism fully, and the novel remains the most widely read entry point to her ideas.

Rand's rejection of altruism is not a celebration of greed—it is a rejection of sacrifice as a moral ideal. Greed, in her framework, is self-destructive: it seeks to gain at others' expense, which violates the principle of trade and treats others as means. Altruism, she argued, is equally destructive because it demands that one give up one's own values, often to those who do not deserve them. Rand's alternative is neither greed nor self-sacrifice but rational self-interest: the pursuit of one's own life and happiness through production, trade, and mutual benefit. Her target was the moral authority of sacrifice itself, not the pursuit of material gain.

Rand acknowledged Aristotle as her only philosophical debt, though she disagreed with much of his system. What she took from him was the primacy of reason and the law of non-contradiction—the idea that reality is what it is, independent of our wishes. She called him 'the master of those who know' and saw his metaphysics as the foundation on which a rational ethics could be built. Her ethics of rational self-interest resembles Aristotelian eudaimonia in emphasizing human flourishing, but Rand replaced his civic virtue with an uncompromising individualism and rejected his teleological biology. Objectivism is, in her own framing, an Aristotelian philosophy for a capitalist age.