The moral system according to which in a doubt of conscience concerning the morality of a certain course of conduct, a middle way between law and liberty is to be taken. When the opinions on both sides are about equally probable, the opinion for liberty may be followed if the doubt concerns the existence of the law (whether there is a law, whether it extends to this case, etc.); but the law must be observed when the doubt concerns the cessation of the law (whether a law that certainly did exist has been fulfilled, whether it has been dispensed with, etc.). For in the former case liberty is in possession, in the latter case the law; and the fundamental principle of this system is "In a doubt the possessor is to be favored." Furthermore, if the opinion for liberty is notably more probable, whether the doubt concerns the existence or the cessation of the law, the opinion for liberty may be followed; if the opinion for law is notably more probable, the law must be observed. The chief defender of this opinion was St. Alphonsus Liguori, the patron of moralists and confessors.
See Also: conscience; morality, systems of; reflex principles; doubt, moral.
Bibliography: j. aertnys and c. a. damen, Theologia moralis, 2 v. (16th ed. Turin 1950) 1:102–119. m. zalba, Theologiae moralis compendium, 2 v. (Madrid 1958) 1:676. d. m. prÜmmer, Manuale theologiae moralis, ed. e. m. mÜnch, 3 v. (10th ed. Barcelona 1945–46) 1:347–348. a. liguori, Theologia moralis, ed. l. gaudÉ, 4 v. (Rome 1905–12) 1:54–89.
[f. j. connell]