UNREASON
irrationality, unreason
(noun) the state of being irrational; lacking powers of understanding
Source: WordNet® 3.1
Etymology
Noun
unreason (usually uncountable, plural unreasons)
Lack of reason or rationality; unreasonableness; irrationality.
Nonsense; folly; absurdity.
Verb
unreason (third-person singular simple present unreasons, present participle unreasoning, simple past and past participle unreasoned)
(transitive, rare) To prove to be unreasonable; disprove by argument.
(rare) To apply false logic or think without logic.
(rare) To make unreasonable; to deprive of reason.
Source: Wiktionary
Un*rea"son, n. Etym: [Pref. un- not + reason.]
Definition: Want of reason; unreasonableness; absurdity. Abbot of Unreason.
See Abbot of Misrule, under Abbot.
Un*rea"son, v. t. Etym: [1st pref. un- + reason.]
Definition: To undo, disprove, or refute by reasoning. [Obs.]
To unreason the equity of God's proceedings. South.
Source: Webster’s Unabridged Dictionary 1913 Edition