Chapter — Marc, Institutiones Morales
Chapter III: On Probable Conscience
St. Alphonsus, I, 40; ed. G., I, p. 21; H. Ap., tr. I, n. 21; Beaudouin, de Consc., q. IV, 1; Gaude, de system. S. Alph., c. II; Ter Haar, de system. mor. antiq. Probab.; Valensise, super system. Theol. mor.... disquisitio, p. 35; Lehmkuhl, I, n. 156; Noldin, I, n. 222; Genicot, I, n. 63.
- Notion. Probable conscience is defined by St. Alphonsus (I, 40): "Conscience by which someone, relying on some probable opinion, forms for himself a practical dictate of reason, from certain reflex or concomitant principles, for acting licitly."
Thus defined, probable conscience is a right rule of morals, since it furnishes a practical and indeed certain dictate concerning the honesty of the action.
Order of things to be said. In probable conscience two things are distinguished: namely the probable opinion itself, on which we rely, and the formation of the practical dictate, which is made through reflex principles by which the use of the opinion is determined. Wherefore there must be treated: 1. the nature of probability; 2. the use of probability.