What does unreason mean?
Unreason means the absence or failure of rational thought and judgment. Used as a noun, it can describe irrationality as a general condition or behavior dominated by emotion, impulse, prejudice, or superstition. The word often appears in formal, literary, or political contexts, where it contrasts irrational conduct with careful argument and evidence: a discussion may “descend into unreason,” while a policy may be condemned as the product of unreason. Although its vocabulary is not obscure, the term sounds more elevated and categorical than everyday alternatives such as “nonsense” or “illogicality.” The related verb, now archaic, means to think or act without reason. Unreason is useful because it names not merely a mistaken opinion but a broader departure from rationality, allowing writers to describe the character or atmosphere of a whole argument, institution, or society.
The absence or failure of reason, rationality, or rational judgment; conduct characterized by irrationality.
"Faced with contradictory claims, the committee abandoned reason for unreason."
Literary and formal; usually critical in tone.
To think or act irrationally; to behave without reason.
"By then the crowd had begun to unreason, responding to rumour with violence."
Archaic and now rarely used outside older or deliberately historical writing.
Rarely used; the noun is normally treated as an uncountable mass noun.
"The novel explores the various unreasons behind the conflict."
Unreason is what reason looks like after it stops asking questions.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does unreason come from?
Unreason was formed in English by combining the negating prefix un- with reason. The word reason was inherited through Old French raison from Latin ratio, a stem also represented in English by rational, rationale, ration, and ratify. The combination developed both as a noun denoting the absence of reason and, historically, as a verb meaning to act irrationally.
Related word forms
How unreason is actually used
The noun is literary and formal, often with a critical or polemical tone. It may refer to irrationality as an abstract condition or to conduct marked by it. The verb is archaic and is now encountered mainly in older literature.
Easily confused with unreason
Unreason is the absence or failure of rational thought, whereas unreasonable describes a person, action, or argument considered deficient in reason.