Harding v. Handy (1826) 24 U.S. 103, was a suit by heirs at law to set aside conveyances obtained from their ancestor. That case established the proposition that extreme weakness of intellect, even when not amounting to insanity, in the person executing a conveyance, may be sufficient ground for setting it aside when made upon a nominal or grossly inadequate consideration. Mr. Chief Justice Marshall, said: "If these deeds were obtained by the exercise of undue influence over a man whose mind had ceased to be a safe guide of his action, it is against conscience for him who has obtained them to derive any advantage from them. It is the peculiar province of a court of conscience to set them aside. That a court of equity will interpose, in such case, is among its best settled principles."