c. 1600, from French posture (16c.), from Italian postura "position, posture," from Latin positura "position, station," from postulus from past participle stem of ponere "to put, place" (see position (n.)).
1620s, literal, from posture (n.). The figurative sense of "take up an artificial mental position" is attested from 1877. Related: Postured; posturing.