The “Four Loves” is a term used by CS Lewis in his book of the same name, which explored the true nature of love through the four distinctive words used for it in Ancient Greek – agápe, éros, philía, and storgē. The book was based on a set of radio talks in the late 1950s given by Lewis.

Storge means affection and captures a certain fondness through familiarity (a brotherly/sisterly love), especially between members of a family or people who have otherwise found themselves together by chance. It is often described as the most natural, emotive and eclectic of the four loves and, as a result, is able to transcend most discriminating factors that exist in the other types of love.

Philia means a particular love between friends, the strong bond existing between people who share a common interest or activity. CS Lewis immediately differentiated this love from the others, describing it as “the least biological, organic, instinctive, gregarious and necessary... the least natural of loves”. The classical world saw this love as the most profound, however, in that it is always freely chosen. CS Lewis wrote that true friendships, like the friendship between David and Jonathan in the Bible, are almost a lost art, and “to the Ancients, friendship seemed the happiest and most fully human of all loves; the crown of life and the school of virtue. The modern world, in comparison, ignores it”.

Eros means romantic or physical love but for CS Lewis it captured love in the sense of “being in love” or “loving” someone, as opposed to simple, raw sexuality.

Agape means charitable love, a love that occurs unconditionally and without any requirements back and CS Lewis saw this as the greatest of all the loves, and as a specifically Christian virtue – unconditional love rather than the attraction suggested by Eros love. This love is selfless, giving and expecting nothing in return. Agape is written about in the famous passage on love in 1 Corinthians 13, and is described as a sacrificial and spiritual love.