Appendix 6. (600).
St. Alphonsus has an excellent passage on practice in which he affirms that his sole desire is to help souls avoid formal sin. His words merit considerable attention, because this was also his motive in his teaching on probable opinion. Formal sin was his great anxiety, and through his teaching on probable opinion he thought he could best help people avoid it. This is another confirmation that our teaching, which differs somewhat from his on the theoretical side, is governed by the same intention and practice as that of St. Alphonsus. But even the theoretical part in which we differ is tempered and mitigated by this holy man through practical asides and exceptions, as we have said - in our theory these are an integral part of the teaching, not exceptions.
Our system is amply confirmed by St. Alphonsus himself when his theory is brought into line with practice. After having set out his teaching on probable opinion he adds: 'So much for theory. In practice, the usual question is whether in choosing opinions we should decide for the rigid or the favourable side. My reply is that where there is question of shielding a penitent from the DANGER OF FORMAL SIN, the confessor must generally, and in so far as Christian prudence suggests, make use of the favourable opinions. But if the favourable opinions make the DANGER OF FORMAL SIN GREATER - and this is the case with the opinions of some authors, for instance, opinions about avoiding occasions of sin and similar matters - it is ALWAYS right that the confessor should use the SAFER OPINIONS. Indeed the healer of souls IS BOUND to use the SAFER OPINIONS which help penitents to preserve their state of grace' (Morale Systema).
This passage tells us all we wish to know. 1. The Saint confesses that his theory cannot always be followed in practice: 'So much for theory. In practice . . .'; we, on the other hand, are seeking 'what can and must be done in practice'. This is the only theory that we are trying to establish. 2. St. Alphonsus says that the confessor cannot always follow favourable opinions, although approved by his theory. He may do so only 'when these opinions help the penitent avoid the danger of formal sin.' This is exactly what we maintain when we distinguish the cases where formal sin is present from those in which it is absent. And 3. If the favourable opinions 'bring closer the danger of formal sin' the confessor must keep to the safer opinion.
In these examples we see how St. Alphonsus' holiness always led him back to the truth.