43. On Vain Observance

Gerafinia, perfectly restored to health from a grave illness of influenza, makes a vow of abstinence and fasting for her whole life, on all Sundays and the days of the Nativity and of Easter. For she has heard that it is an efficacious and infallible remedy for preventing a relapse. And she holds this as altogether certain, since in fact she has now persevered in perfect bodily health for three years.

Q. 1. What is vain observance? - 2. Is Gerafinia guilty of superstition; and is she bound by the vow?

R. To the first, cf. I. M. 478 seqq. To the second: Gerafinia is guilty of superstition. The reason is that fasting, observed on the aforesaid days, is not of itself an infallible means for preventing a relapse into influenza. But she resolved to observe it with certain faith in the effect that would follow.

Besides, she is not bound by the vow. For the cult is superfluous, foreign to the custom of the Church, and bearing singularity before itself. Hence a vow of fasting ordinarily on Sundays and on the more solemn feasts of the Church is null, especially when the one vowing by no means observes fasting on other days. Nevertheless, superstition being excluded, of itself it would not exceed venial sin. Indeed it would not even be venial if someone fasted from mortification. But it is better to abstain from such a fast, and therefore the doctors commonly teach that a fast promised on Sunday can be fulfilled on Saturday; and, if someone has vowed to fast for a month, that he is not bound on Sunday. But if someone accustomed to fast on other days sometimes fasts, from some good end, on Sunday, he does not sin. - Reuter, p. 2, n. 427; Lig. 4; G. 258-260; I. M. 466.