According to the allegations of the bill, the plaintiff became a party to the note from which he prays to be relieved, and transferred his stock, in consideration that the defendant would not prosecute his son for perjury, and under a threat from it that otherwise his son would be prosecuted. The transaction was illegal; Pub. Sts. c. 205, § 27; Gorham v. Keyes, 137 Mass. 583; and if the parties stood on an equal footing, neither of them would have a remedy against the other. Atwood v. Fisk, 101 Mass. 363. But it is well recognized that, although both parties are chargeable with knowledge that their agreement is contrary to some rule of law, yet if one of them acts under duress, or what the law regards as undue influence on the part of the other, they do not stand on an equal footing, and the weaker one may be granted affirmative relief. Worcester v. Eaton, 11 Mass. 368, 376. Belding v. Smythe, 138 Mass. 530, 533. It is settled that such threats as are alleged to have been addressed to the plaintiff constitute duress. Harris v. Carmody, 131 Mass. 51. See Rau v. Von Zedlitz, 132 Mass. 164. And accordingly it has been decided in other jurisdictions, in cases like the present, that the plaintiff was entitled to relief in equity. Foley v. Greene, 14 R. I. 618. Schoener v. Lissauer, 107 N. Y. 111. Williams v. Bayley, L. R. 1 H. L. 200. Davies v. London & Provincial Ins. Co. 8 Ch. D. 469, 477. See Sharon v. Gager, 46 Conn. 189; Rau v. Von Zedlitz, 132 Mass. 164, 167-169.
In Atwood v. Fisk, ubi supra, cited as establishing a different conclusion, it seems to have been found or assumed that the plaintiffs had not been subjected to any undue pressure, as the decision states that there was “ no such inequality in position, or abuse of advantages, as to entitle them to the aid of the court on the ground of public policy.” Demurrer overruled.