Introduction to Objectivist Epistemology, published in 1979, is Ayn Rand's essentialised summation of the Objectivist theory of concepts and solution to the problem of universals. The book deals with the mental processes of conceptualization, the nature of definitions, distinguishing legitimate concepts from "anti-concepts," the hierarchical nature of knowledge, and what constitutes valid axiomatic knowledge. The book also includes an essay by Leonard Peikoff in which he argues against Immanuel Kant's theory of analytic propositions and synthetic propositions. These works were originally serialized in The Objectivist from 1966 to 1967, then published in a paperback by The Objectivist in 1967.
The second edition of Introduction to Objectivist Epistemology contains a transcript of Ayn Rand's "Question-and-Answer" session with various professors of philosophy, mathematics, and physics about her epistemology that followed a lecture series she gave on epistemology between 1969 and 1971. Introduction to Objectivist Epistemology describes axiomatic concepts as "the identification of a primary fact of reality, which cannot be analyzed, i.e., reduced to other facts or broken into component parts". The three axiomatic concepts identified in Introduction to Objectivist Epistemology are "existence", "identity" and "consciousness".