The Four Loves
Storge-Affection
Affection is fondness through familiarity, especially between family members or people who have otherwise found themselves together by chance. It is described as the most natural, emotive, and widely diffused of loves: natural in that it is present without coercion; emotive because it is the result of fondness due to familiarity; and most widely diffused because it pays the least attention to those characteristics deemed “valuable” or worthy of love and, as a result, is able to transcend most discriminating factors. Ironically, its strength is also what makes it vulnerable. Affection has the appearance of being “built-in” or “ready made”, says Lewis, and as a result people come to expect, even to demand, its presence—irrespective of their behavior and its natural consequences.
Phileo-Friendship
Phileo is the love between family and friends. Friendship is a weak bond existing between people who share common interest or activity. Lewis explicitly says that his definition of friendship is narrower than mere companionship.
Eros-Romance
Eros is love in the sense of ‘being in love’. This is distinct from sexuality, which Lewis calls Venus, although he does spend time discussing sexual activity and its spiritual significance in both a pagan and a Christian sense. He identifies eros as indifferent. It is Venus that desires the sexual aspect of a relationship, while Eros longs for the emotional connection with the other person.
Agape-Unconditional love
Charity is the love that brings forth caring regardless of circumstance. Lewis recognizes this as the greatest of loves, and sees it as a specifically Christian virtue. The chapter on the subject focuses on the need of subordinating the natural loves to the love of God, who is full of charitable love.