Aquinas's Invocation of the Demons

In every incantation or wearing of written words, two points seem to demand caution. If is connected with invocation of the demons, it is clearly superstitious and unlawful. One should take care lest it contain anything false, because in that case also, the effect would not be ascribed to god who does not bear witness to a falsehood. But you can wear an object around your neck for healing or protection as long as it only contains wholesome christian words and symbols. And wearing it is just an enacted prayer. Similarly, if you're taking medicines or making medicines, you can say prayers like the lord's prayer and make the sign of the cross, but don't go doing strange