Adverb
In an irrational manner.
Source: Webster's dictionaryIn fact, all the additional knowledge gained by an irrationally constituted society may but enlarge and enhance the powers of death and destruction. Paul A. Baran
Irrationally held truths may be more harmful than reasoned errors. Thomas Henry Huxley
Human beings are the only creatures who are able to behave irrationally in the name of reason. Ashley Montagu
Great creativity is astonishingly, absurdly, rationally, irrationally powerful. Andy Hobsbawm
No one actually needs another person or another person's love to survive. Love is when we have irrationally convinced ourselves that we do. Gabrielle Zevin
The scientific spirit is of more value than its products, and irrationally held truths may be more harmful than reasoned errors. Thomas Henry Huxley