What is love? Psychotherapist Mark Vernon looks at Freud's ideas on the Greek god Eros, which he saw as a kind of life force running through us, shaping our desires and passions

Freud is often thought of as reducing everything to sex, but in his view, for humans even sex isn't even really about sex. Although he started off thinking that sex was about biological release of pressure - like a steam engine - he quickly realised, from working with patients, that it was more about fantasy and imagination.

Humans want far more from sex than just reproduction or physical stimulation. Freud used the Greek god Eros as a metaphor for the unconscious forces that motivate us. He thought of Eros as a something like a force field of love, going beyond the simple one-to-one sexual attraction to a broader desire to get more out of life. Eventually he saw Eros as a desire for unification with the whole of humanity that is built into the dynamic of life itself - the yearning that wants to pass life on in children, the passion for creativity and discovery,

Presenter: Mark VernonProducer: Jolyon Jenkins.