In the recent Gotthelf/Salmieri piece that I linked to below, it says as follows:
"Rand’s virtue-focused rational egoism differs from traditional eudaimonism in that Rand regards ethics as an exact science. Rather than deriving her virtues from a vaguely defined human function, she takes 'Man’s Life' – i.e. that which is required for the survival of a rational animal across its lifespan – as her standard of value."
A couple points:
1. What is the difference between Rand's ethics and "traditional eudaimonism"? Why didn't the authors give us a single example of whose ethics is different (I realize that they had limited space, but ARIans love to tell us that Rand is so different without providing even a name of another philosopher to compare).
2. The language concerning the "survival of a rational animal across its lifespan" is unusual. The "lifespan" idea doesn't have any precedence in the Objectivist literature, from what I can tell.