What is "irish bull"

An Irish bull is a ludicrous, incongruent or logically absurd statement, generally unrecognized as such by its author. The inclusion of the epithet Irish is a late addition.

The "Irish bull" is to the sense of a statement what the dangling participle is to the syntax. A jarring or amusing absurdity is created by hastiness or lack of attention to speech or writing.

Although, strictly speaking, Irish bulls are so structured grammatically as to be logically meaningless, their actual effect upon listeners is usually to give vivid illustrations to obvious truths. Hence, as John Pentland Mahaffy, Provost of Trinity College, Dublin, famously observed, "an Irish bull is always pregnant", i.e. with truthful meaning. The "father" of the Irish bull is often said to be Sir Boyle Roche, who once asked "Why we should put ourselves out of our way to do anything for posterity, for what has posterity ever done for us?". Roche may have been Sheridan's model for Mrs Malaprop.

Yogi Berra and Samuel Goldwyn were famous American mis-speakers. They are the Mother Geese of American Irish bulls.

The Irish bull can be a potent form of self-conscious equivocation and satire in the hands of a wit's sharp tongue. As such, it is associated particularly with new or marginalized populations, such as the Irish in Britain in the nineteenth century, or the Jews and Germans in America in the Early Twentieth Century.