In Re the Will of Covington

Courts of equity, to prevent injustice to one who relies on the spoken word or act of another, fashioned-a rule of conduct called estoppel in pais. The rule prohibits or estops the speaker or actor from controverting what he had previously asserted. Lord Coke said: “It is called an estoppel or conclusion, because a man’s own act or acceptance stoppeth or closetb up his mouth to allege or plead the truth.”

Adams, J., said: “Equitable estoppel in pais owes its origin and development to the notion of justice promulgated by courts of chancery. It embraces estoppel by conduct which rests upon the…