Mental Reservation is a term for withholding or failing to disclose something that affects a statement, promise, oath, etc., and which, if disclosed, would materially vary its import. As this is a false and deceitful way of acting, it can not be approved by true morality. The Jesuits, indeed, allowed and taught their pupils to delude people by all kinds of mental reservations and deceitful intentions. With many of them the end sanctified the means, and so they taught that even deceit by false promises and perjuries is allowable, if only good things were attained thereby in the end. They defended this manner of action by the shallow pretext that mentally something very different has been promised or sworn to from what the spoken words declared. SEE CASUISTRY; SEE MORAL PHILOSOPHY.