First published in installments in Rand's journal, The Objectivist, July 1966 through February 1967, the work presents Rand's proposed solution to the historic problem of universals, describes how the theory can be extended to complex cases, and outlines how it applies to other issues in the theory of knowledge.

Accordingly, Rand defines "concept" as: a "mental integration of two or more units possessing the same distinguishing characteristic(s) with their particular measurements omitted.

"[1] The monograph includes chapters outlining the Objectivist theory of how higher-order concepts are formed ("Abstraction from Abstraction"), how measurement applies to phenomena of consciousness, the nature and cognitive significance of definitions (including a defense of essence as being "epistemological" not "metaphysical"), a theory of axiomatic concepts, not axiomatic propositions, as being the base of conceptual cognition, the introduction of a "principle of unit economy" as crucial for judging and justifying and conceptual-level content, and a call for the wholesale rejection of the Kantian turn in philosophy, seeing Kant as falsely opposing the identity of consciousness to its cognitive validity—i.e., to its being conscious.

The most active among those questioning Rand on the meaning and implication of her theory were John O. Nelson, George Walsh, Leonard Peikoff, Allan Gotthelf, and Harry Binswanger.

Rand's title essay was originally serialized in The Objectivist from July 1966 to February 1967, then reprinted by the Nathaniel Branden Institute later in 1967 as a booklet.