Further discussions:
Tara Smith, Viable Values: A Study of Life as the Root and Reward of Morality (Lanham, Maryland: Rowman & Littlefield Publishers, Inc., 2000), pp. 83-123.

Tara Smith, Ayn Rand's Normative Ethics: The Virtuous Egoist (Cambridge: Cambridge University Press, 2006), pp. 20-22.