In City of God
Augustine tried to answer how immaterial Angels (and we might also add immaterial human souls/minds)* could suffer from physical fire in hell. He said:
"Therefore, though the devils have no bodies, yet their spirits, that is, the devils themselves, shall be brought into thorough contact with the material fires, to be tormented by them; not that the fires themselves with which they are brought into contact shall be animated by their connection with these spirits, and become animals composed of body and spirit, but, as I said, this junction will be effected in a wonderful and ineffable way, so that they shall receive pain from the fires, but give no life to them." - Augustine, City of God, 21, 10
In support of this Augustine brings up the story of Lazarus, where we read: "Then he cried and said, Ã¢â‚¬ËœFather Abraham, have mercy on me, and send Lazarus that he may dip the tip of his finger in water and cool my tongue; for I am tormented in this flame.Ã¢â‚¬â„¢" (Lk. 16:24)
This brings up a few questions in my mind, if I am understanding this teaching correctly. First, I know that the passage about Lazarus was brought up at the Council of Ferrara-Florence when discussing purgatory, but did they also bring up this issue of how physical flames could hurt an immaterial nature? Second, has anyone (e.g., Aquinas) since Augustine attempted to further develop how exactly fire could effect immaterial beings? And third, do Catholics presently hold to the idea that there will be fire as a physical part of an actual physical place, or do they consider hellfire to be a non-physical aspect of a state of being
* Actually I think that they are only immaterial in comparison to the rest of creation, and are to some extent material in comparison to God, and Augustine essentially accepts this idea himself (Epistle 166
), but that isn't really relevant in this post as Augustine assumes immateriality in trying to answer this problem.