VANE OBSERVANCE. — It is one of the forms of non-cultic superstition, by which superstitious practices, unsuited to the end intended, are performed with a superstitious intent.
Such are the art of acquiring knowledge without study, e.g., by the use of certain words, certain figures, or special prayers and fasts; the art of healing by disproportionate means, such as the use of prayers, incantations, exorcisms, attributing to them an infallible efficacy *ex opere operato*; the art of warding off evils and dangers by the use of lucky charms, amulets, etc. Vane observance may involve a recourse, explicit or implicit, to the devil.
Indeed, whoever, in order to obtain a certain effect, employs a vain and useless means, that is, one neither destined by nature nor by God or the Church to produce such an effect, cannot expect such a result except from the devil.
The morality of vane observance is generally deduced from the agent’s very intention, from the effects he foresaw, and from the dangers of sin to which he exposed himself. If the observances involve an explicit invocation or pact with the devil, there is evidently a grave sin (cf. Deut. 18:10–11; Lev. 19:31; 20:27), also because no temporal advantage can compensate for the spiritual harm that follows from demonic invocation (*Sum. Theol.*, II-II, q. 95, a. 2 and 4). Even when there is no explicit pact, if one knowingly and superstitiously employs a means unsuited to a given end, one commits, in itself, a grave sin, because implicitly one desires diabolical intervention. However, in this case, one is usually excused from grave fault, since the act is generally performed either out of mere curiosity, simplicity, or ignorance.