A term used to describe an attempt to evade a perplexing moral situation by restricting the meaning of words used in an act of communicating. Not wanting to lie, a person may at the same time not want to tell the truth, because it would involve him or others in difficulty. If he accepts the traditional and still common teaching of Catholic moralists, he knows that he is bound by a negative precept never to lie in any circumstances, yet there is no positive precept binding him to tell the whole truth in all circumstances. Silence would often be the best solution, but in some cases silence itself would provide a damaging answer. An alternative to silence, suggested to extricate the beleaguered conscientious individual from his dilemma, is the device known as mental reservation.
Kinds of Mental Reservation. The term has been understood in two senses. In the strict sense it means giving
utterance to only part of one's judgment while retaining in mind or whispering inaudibly another part necessary to make the statement objectively truthful. In the classical example, Titius privately said to a woman that he would take her for his wife, although he had no intention of marrying her. Later, when asked by a judge whether he had said he would take the woman for his wife, he replied that he had not, understanding that he had not spoken the words with the intention of marrying the woman.
In the broad sense, mental reservation is the use of equivocation or ambiguity to conceal the truth. What is said is not objectively untruthful, but it is phrased in such a way that it is possible, indeed even probable, that the true meaning of the words will escape the hearer, and that he will understand them in a sense in which they are not true.
History of the Problem. The need of protecting oneself against intrusive or unjust questioning so perplexed some of the early Fathers of the Church that in their solution of difficulties of this kind they seemed to tolerate lying. With St. Augustine, however, strong convictions were established on the subject of veracity. During the Middle Ages scholastic theologians accepted and expanded upon, but never deviated from, Augustine's definition of a lie and his teaching that to utter the opposite of what one holds to be true is intrinsically evil. In the 16th century this tradition began to weaken among some theologians. Martin aspilcueta (d. 1586) defended the licitness of mental reservation in the strict sense in his discussion of the classical example mentioned above. His near contemporary, Francisco de Toledo, and later theologians, such as Raynaud, Sánchez, Suárez, and Lessius, either espoused the doctrine of strict mental reservation or accorded it strong probability. Other theologians, such as Cajetan, Soto, Laymann, De Lugo, and Azor, along with most other Catholic moralists, repudiated it. With the condemnation by Innocent XI of one of the propositions of Tomas Sánchez (H. Denzinger, Enchiridicu symbolorum 2126), attempts to justify strict mental reservation came to an end, and thereafter it was considered permissible only if the meaning of the term was so broadened as to signify little more than ambiguity of speech.
Moral Evaluation. St. Thomas taught that to lie is one thing, and to keep the truth hidden is another; to affirm a restricted truth is not to deny a more extensive one (Summa Theologiae 2a2ae, 109.4). A man can affirm that he had coffee and toast for breakfast without denying that he had an egg, or he might affirm that he has a lesser amount of money in his pocket without denying that he also has a greater amount. So long as he has reasonable cause to conceal part of the truth, he does no wrong, provided, of course, that he is careful not to indicate that he has "only" so much to eat or that he has "only" so much money.
Similarly, a person could make a statement that has all the appearances of a reply to a question put to him, but which in fact is not, owing to some circumstance known to the speaker, which the hearer could know also but may not consider. If, for example, a wife, who has been unfaithful but after her lapse has received the Sacrament of Penance, is asked by her husband if she has committed adultery, she could truthfully reply: "I am free from sin." In any of these cases the speaker does not question the hearer's right to know a truth. He presents the truth as discoverable but not disclosed. He has made no false statement, but has allowed an admissible ambiguity, foreseeing a possible, or even probable, deception.
If deception follows from a broad mental reservation it is a by-product effect. Concealment of a truth legitimately hidden is the primary intention of the one who speaks evasively. Deception does not follow necessarily from the statement itself but from the circumstances of its utterance, especially from the dispositions of the hearer. By his own simplicity, ignorance, prejudices, or malice, a hearer may be deceived in listening to the evasive words of a broad mental reservation. The words themselves lack clarity and distinctness, which the hearer supplies for himself from his own assumptions. The words do not, however, distort the true, though vague, communication made by the speaker, and consequently they are not a lie.
Because deception of one's neighbor is an evil, one needs a just and proportionately grave cause to have recourse to evasive speech or writing. Simplicity in speech is to be regarded as obligatory under ordinary circumstances.
Moreover, in some circumstances the questioner may have a strict right to know the whole truth, and when such is the case, no type of mental reservation is allowable in answering a question. Consequently, mental reservation, even in the broad sense, is never tolerable when replying to questions of a superior in matters pertaining to his jurisdiction, or in formulating strict bilateral contracts, or in replying to a judge asking legitimate questions or to a confessor concerning something he needs to know for the proper administration of the Sacrament of Penance.
Bibliography: c. r. billuart, "Tractatus de religione et vitiis oppositis," 9.1–2, v.7 of Summa Sancti Thomae, 10 v. (new ed., Paris 1874–86). d. prÜmmer, Manuale theologiae moralis, ed. e.m. munch, 3 v. (10th ed. Barcelona 1945–46) 2:171–174. j. b. brosnan, "Mental Restriction and Equivocation," The Irish Ecclesiastical Record 16.2 461–470. a. vermeersch, Dictionnaire Apolgétique de la Foi Catholique (Paris 1911–22) 4:958–982.
"Mental Reservation." New Catholic Encyclopedia. . Encyclopedia.com. (August 17, 2018). http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/mental-reservation
"Mental Reservation." New Catholic Encyclopedia. . Retrieved August 17, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/mental-reservation