[eastsider]

Meanwhile, the context of your final words ... (as in man (species) is a rational animal (genus)) -- did not have bodies ... seems to contradict what you're saying.

Genus and species are rational concepts. They have no bodies. If you're suggesting otherwise, I'm all ears.

Compare Rand's words to your explanation about Aristotle's primary/secondary substance distinctions, and you can see how Rand improved on Aristotle's epistemology.

I seriously doubt that Ayn Rand herself would have considered the proposition that one's nature (in Randian terms, a defined concept), rather than the person, is the agent of human behavior an improvement.

[thinktwice]

I seriously doubt that Ayn Rand herself would have considered the proposition that one's nature (in Randian terms, a defined concept), rather than the person, is the agent of human behavior an improvement.

Question -- An improvement to what?

Comment -- Ayn Rand would probably say that one's nature is a subset of one's person -- leaving the person being the agent of one's behavior. The "God made me do it" defense won't work in the real world.