[OldNavyVet]

Is it from Introduction to Objectivist Epistemology?

Yes, and I found it quickly using "The Ayn Rand Lexicon," pg 149.

That entire Lexicon is on the internet. Quote comes from http://aynrandlexicon.com/lexicon/epistemology.html

[albionin]

Thanks. That’s just about the only book of hers that I haven’t read and I didn’t recognize the quote.