1. irrational - Noun
2. irrational - Adjective
Not rational; void of reason or understanding; as, brutes are irrational animals.
Not according to reason; absurd; foolish.
Not capable of being exactly expressed by an integral number, or by a vulgar fraction; surd; -- said especially of roots. See Surd.
Source: Webster's dictionaryFear of serious injury cannot alone justify suppression of free speech and assembly. Men feared witches and burnt women. It is the function of speech to free men from the bondage of irrational fears. Louis Brandeis
Having a child is surely the most beautifully irrational act that two people in love can commit. Bill Cosby
Nothing defines humans better than their willingness to do irrational things in the pursuit of phenomenally unlikely payoffs. This is the principle behind lotteries, dating, and religion. Scott Adams
What we call rational grounds for our beliefs are often extremely irrational attempts to justify our instincts. Thomas Henry Huxley
Markets can remain irrational longer than you can remain solvent. John Maynard Keynes
When we approach history, we are dealing with a conglomeration of irrational continua. Those who deal with history by nonrational processes are the ones who make history, the actors in it. Carroll Quigley