The system of rewards and punishments attached by the legislator to the observance or violation of a law.
A moral sanction has a two-fold purpose, one deterrent, influencing through the hope of reward and the fear of punishment, the other retributive, rewarding the observance and through proper punishments procuring the restoration of violated moral order.
Sanctions constitute the necessary guarantee of the obligating character of the moral law.
Experience proves their necessity and that the sanctions of this life such as remorse of conscience, sufferings, social and legal penalties, etc., are altogether inadequate to prevent violation of the moral code.
Divine Wisdom and Justice demand a truly adequate sanction.
Such complete and final sanction is not to be found in this world of struggle between good and evil, where the forces of evil at times seem victorious, but in the future life with its eternal rewards or happiness and the eternal punishments or misery through which goodness and virtue as well as Divine Justice are finally triumphant.
New Catholic Dictionary