Video from The Thomistic Institute
“How art thou fallen from heaven, O Lucifer, who didst rise in the morning? How art thou fallen to the earth, that didst wound the nations?” (Isaiah 14:12) Have you ever wondered how the angels could possibly have fallen? They had it all—they were so close to God. Why then the tragic catastrophe? Angelic Knowledge and Choice (Aquinas 101) - Fr. Gregory Pine, O.P." from video introduction.