XII–XIII. Permission and hardening of fallen angels; names of unclean spirits
XII. Permission is that by which, with divine power temporarily set aside, certain angels are allowed to fall. XIII. Hardening at by which the fallen, grace denied, are made firm in evil.
They are also called unclean spirits (Luke 11:24), worthless spirits (1 Samuel 16:14), spirits of error (1 Timothy 4:1), Satan, the Devil, the ancient serpent, the dragon, angels of Satan (Revelation 12:9), father of the lie (John 8:44), spiritual wickedness (Ephesians 6:12), roaring lion (1 Peter 5:8), demons (Luke 11), satyrs (Leviticus 17:7), hairy ones (Isaiah 13:21; 34:14). The reason for the naming is that they are spirits created by God indeed, but who by free will fell away at the beginning from the truth in which they were made, and became horrible adversaries of both God and human beings, and are kept in eternal chains for judgment (John 8:44; 2 Peter 2:4; Jude 6).
Latin
XII. Permissio est, qua suspensa efficientia divina angeli quidam labi sinuntur. XIII. Obfirmatio est, qua lapsi negata gratia in malo firmantur. Dicuntur etiam Immundi spiritus (Luc. 11:24), spiritus nequam (1 Reg. 16:14), spiritus erroris (1 Tim. 4:1), Satan, Diabolus, serpens antiquus, draco, angeli Satanae (Apoc. 12:9), pater mendacii (Ioh. 8:44), spiritualis nequitia (Eph. 6:12), leo rugiens (1 Pet. 5:8), daemonia (Luc. 11), satyri (Lev. 17:7), pilosi (Es. 13:21; 34:14). Ratio denominationis est quia sunt spiritus a Deo quidem creati, sed qui a veritate in qua conditi erant in principio libera voluntate defecerunt, et horribiles tam Dei quam hominum adversarii facti sunt, et aeternis ad iudicium vinculis servantur (Ioh. 8:44; 2 Pet. 2:4; Iudae 6).