Hĕr'e-sy, n.

n. [Gr. αἵρεσις, a taking, a taking for one's self, a choosing, a choice, a sect, a heresy, from αἱρεῖν, to take, choose; Lat. hæresis, Fr. hérésie, It. eresia, Pg. heresia, heregia, Pr. & Sp. heregía.]

1Sense 1. An opinion taken upon opposition to the established or usually received doctrine, tending to promote a division or party; the belief of a sect or party; a persuasion;—usually, but not necessarily, said in reproach; especially (Theol.), lack of orthodox or sound belief; heterodoxy.

New opinions Divers and dangerous, which are heresies, And not reformed, may prove pernicious. Shak.

2Sense 2. (Law.) An offense against Christianity, consisting in a denial of some essential doctrine, publicly avowed, and obstinately maintained. Blackstone.

“When I call dueling, and similar aberrations of honor, a moral heresy, I refer to the force of the Greek αἵρεσις, as signifying a principle or opinion taken up by the will for the will's sake, as a proof or pledge to itself of its own power of self-determination, independent of all other motives.” Coleridge.