Question Six
Whether it is a sin to foretell future things through dreams
It is asked whether it is a sin to foretell future things through dreams.
To this it is answered as follows: future things can be predicted through dreams in four ways.
First, this can occur from natural reasoning; and in this way all future things which have their effects in their causes can be cognized. To predict such things is lawful and is not divination, as is evident above in the first chapter concerning divination.
Second, future things can be predicted from a corporeal complexion or disposition, as physicians do. This is lawful and is not to divine.
Third, it can occur from a revelation of God, as Joseph and Daniel did in Genesis 40 and Daniel 2. Through divine revelation they saw presages of future things, and therefore they expounded the revelation made to them by God and narrated it to others.
Hence Joseph said to the two eunuchs who had dreams and did not know their interpretations: “Does not interpretation belong to God? Tell me what you have seen,” in Genesis 40.
And in Daniel 2 it is said that the mystery was revealed by God through a vision. Hence it adds: “There is a God in heaven who reveals mysteries.”
Nevertheless, in no dreams, considered in themselves, ought faith and hope to be placed with certainty, unless it were certain to someone that something had been revealed for certain through dreams, or in dreams, by the Lord. Hence neither Joseph nor Daniel observed dreams by placing their hope in them. Rather, they expounded the things which were revealed to them by God through dreams, as is evident.
Fourth, future things can be predicted in dreams from the illusion and revelation of demons, with whom those persons have pacts: either express pacts, because they invoke them for this purpose, or tacit pacts, because divination of this kind extends itself to that to which it cannot extend itself. Such divination is illicit and superstitious.
Hence this is proved in Leviticus 19: “You shall not observe dreams”; and Deuteronomy 18: “Let there not be found among you one who observes dreams”—namely, one who either has a pact with a demon or places hope in dreams.
These things are from blessed Thomas, Second Part of the Second Part, question 95, article 6.