unreason
Definitions
Lack of reason or good sense; irrationality.
Absurd or foolish behavior or thought.
Examples
The sudden outburst of unreason from the crowd caught the security team off guard.
It is difficult to negotiate with someone who operates entirely out of unreason and emotion.
History is often a cycle of reason followed by periods of collective unreason.
Synonyms
irrationality illogic absurdity folly senselessness incoherence madness