The Four Loves by C.S. Lewis
The Four Loves is a 1960 book by C. S. Lewis which explores the nature of love from a Christian and philosophical perspective through thought experiments. The book was based on a set of radio talks from 1958.
C.S. Lewis’s famous work on the nature of love divides love into four categories: Affection, Friendship, Eros and Charity. The first three are loves which come naturally to the human race.
Charity, however, the Gift-love of God, is divine in its source and expression, and without the sweetening grace of this supernatural love, the natural loves become distorted and even dangerous.