Controlling force; irresistible compulsion; a power or Impulse so great that it admits no choice of conduct. When it is said that an act is done “under necessity,” it may be. in law. either of three kinds of necessity: (1) The necessity of preserving one’s own life, which will excuse a homicide; (2) the necessity of obedience, as to the laws, or the obedience of one not sui juris to his superior; (3) the necessity caus ed by the act of God or a stranger. See Jacob; Mozley & Whitley. A constraint upon the will whereby a person is urged to do that which his judgment disapproves, and which, it is to be presumed, his will (if left to itself) would reject. A man, therefore, is excused for those actions which are done through unavoidable force and compulsion. Wharton.