In Greek thought, eros connotes desire, longing, disequilibrium, and is generally sexual in nature. However, in Plato (especially the Symposium and Phaedrus), although eros may start with a particular person as its object, it soon becomes transferred from the particular person to their beauty (a characteristic that in principle another person could possess to the same or a greater degree), and finally it gravitates towards immaterial objects such as the form of beauty itself. The desire for immaterial beauty is a kind of recollection of the vision of forms (such as those of justice, wisdom, and knowledge) that the soul was able to perceive on the ‘plains of truth’ in its previous life. Bodily beauty induces remembrance of this state, anamnesis, and enables the soul to begin to climb the ladder back to spiritual truth. The philosopher, the poet, the lover, and the follower of the muses (or creative artist) are all inspired by the divine power of eros, which dictates the passionate pursuit of the truly real, pure intellectual light, through beauty, wisdom, and the arts of the muses. It is not often recorded how persons who believe themselves to be beloved are supposed to react to these fleshless rivals, although Dante’s Beatrice is the principal example of a beloved person both initiating and then conducting a spiritual ascent of this kind. Unfortunately, however, before conducting Dante up to the highest circles of Paradise, she has to be dead. The idea of beauty as the visible trigger of a spiritual ascent was transmitted to the medieval world through Neoplatonism, and especially the City of God of Augustine.

Philia in Greek thought is more akin to friendship, and includes fondness and desire for the good of another. In Aristotle, quite stringent conditions are required for reciprocal and recognized philia: familiarity, virtue, and equality. Agapē is the Christian addition to the forms of affection here recognized, and suggests a less focused, universal benevolence that pays little or no regard to reciprocity. See also apathy, sex.