Professor Kreeft, What is this “spirit” of which angels are made?
Spirit means essentially two things:
1. The power of thinking—conscious, deliberate, rational understanding. Not sense-perception; that’s the work of a bodily organ, like the eye.
2. The power of willing and choosing and deliberately loving. Not sensory appetite; that’s the work of a bodily function, like hunger. God and angels are pure spirits. Humans and intelligent extraterrestrials (if there are any) are spirit-body compounds.
Ghosts are the spirits, or souls, of human beings whose bodies have died. They may hover around the earth “haunting” material places, usually houses. There seem to be four possible reasons for this:
1. They don’t yet realize they are dead.
2. They were so attached to their material places or possessions that they can’t detach themselves from them and leave.
3. They are working out some purification, penance,
4. They are consoling their loved ones who have been bereaved. Angels, in contrast, did not have human bodies in the first place and never will. Ghosts once had human bodies and will receive new resurrection bodies in heaven if they go there.