Further discussions:
Ayn Rand, "The Objectivist Ethics," in The Virtue of Selfishness: A New Concept of Egoism (New York: The New American Library, 1964), pp. 16, 19-21.
Tara Smith, Ayn Rand's Normative Ethics: The Virtuous Egoist (Cambridge: Cambridge
University Press, 2006), pp. 48-74.