Chapter Nine of the Third Decade
On divination, commerce, and invocation of demons, concerning which sixteen little questions will be resolved
Question One of Chapter Nine of the Third Decade
Whether anyone can predict future things through invocation of demons without sin
It is asked whether anyone can predict future things through invocation of demons without sin.
It is answered that future things can be predicted and known in three ways.
In one way, naturally, from causes which act in most cases and frequently; knowledge of such things is not divination but foreknowledge. Hence the rising of the sun tomorrow, or when a physician predicts future health and an astronomer a future eclipse or rain, is not prediction by divination but foreknowledge from necessary causes or causes acting frequently.
In a second way, future things can be known by a revelation of God; in this way too foreknowledge of future things is not divination. Hence, if anyone announces future contingents when God reveals them, he then does not divine—that is, he does not make what is divine, but rather receives what is divine.
In a third way, future things can be known through a demon’s indication, and divination concerns these things. For, as Augustine says in the book On Christian Doctrine, divination is the usurpation of foreknowing future things from a certain pestilential association of human beings and demons. To use divination in this third way is unlawful and always a mortal sin.
This is proved by authorities and arguments.
First, by the authority of Deuteronomy 18, which says: “Let there be no one who consults pythonic spirits or diviners.” Pythonic spirits are so called from Pythian Apollo, who was said to be the author of divining, as Isidore says.
Therefore it is said in cause 26, question 5, chapter Qui divinationes: “Those who seek divinations shall lie under the rule for five years according to the established degrees of penance.”
Second, the same thing is proved by four arguments.
First, from the character of the manner, thus. The person who usurps in an undue manner what belongs to God, when God does not reveal it, sins mortally. Diviners do this, pretending themselves to be filled with divinity but conjecturing future things for human beings by a certain fraudulent cunning. Therefore they sin mortally.
Second, from the character of the assistance, thus. If anyone assumes the assistance of demons in order to know or do something, he sins gravely. But every divination arises from the operation of demons, either because demons are expressly invoked to manifest future things or because demons interpose themselves in vain inquiries into future things so that they may entangle human minds in vanity. Therefore every divination is a grave sin.
Third, from the character of the pact, thus. If anyone makes use of a tacit or express pact with demons, he sins gravely—that is, mortally. But divination is of this kind, because diviners either offer sacrifice to a demon or assume the assistance of demons. Therefore it is a mortal sin.
But if it is argued to the contrary thus: what Christ performed and did is neither unlawful nor mortal sin. But he himself asked the demon what his name was, and it replied, “Legion, and we are many,” as is found in Mark 5 and Luke 8. Therefore anyone may lawfully consult demons.
To this Thomas responds in the Second Part of the Second Part, question 95, article 1, saying that it is one thing to ask something of a demon and another thing to invoke a demon.
The first—namely, to ask something of a demon who presents himself spontaneously—is sometimes lawful for one’s own usefulness or that of others, especially when the demon can be compelled by divine power to speak true things, as is evident concerning Christ above and concerning blessed Martin and other saints.
The second, however—namely, to invoke a demon in order to acquire from him knowledge of hidden things—is never lawful.
Hence it is never lawful, for the sake of some bodily or temporal utility—for example, the finding of lost things, which the devil knows and knows who found—to inquire of him or to use his assistance in matters of this kind.
The reason is that no temporal utility can be compared with the loss of spiritual salvation which threatens from inquiry into hidden things through invocation of demons.
These things are from Thomas in the place cited above, Johannes de Turrecremata, cause 26, question 5, chapter Nec mirum, and Raynerius under the title On Divination.