Although there are many kinds of love, erotic love has been celebrated in art and poetry as life's most rewarding and exalting experience, worth living and dying for and bringing out the best in ourselves. And yet it has excused, and even been thought to justify, the most reprehensible crimes. Why should this be? This Very Short Introduction explores this and other puzzling questions. Do we love someone for their virtue, their beauty, or their moral or other qualities? Are love's characteristic desires altruistic or selfish? Are there duties of love? What do the sciences -...