In Plato's Symposium, eros occupies the lowest rung on the so-called ladder of love. It is the love for something one doesn't have—a love that manifests itself in a desire for another person's body, for example. For Plato, speaking through Socrates, who in turn speaks through the wise woman Diotima, eros is a lower form of love because it is concerned with specific objects in the world around us, the world of space and time.

In the allegory of the cave in Plato's Republic, this world is likened to a shadow play of images against a cave wall. Though real, objects in the world of space and time aren't as real as the Forms or Ideas, those unchanging abstract concepts of which sensible objects—things we can see, smell, hear, taste, and touch—are mere copies. For instance, there is the Form of Beauty. There are also beautiful objects, such as beautiful people, flowers, or sunsets, which, in their own individual way, are copies of Beauty in the abstract.

Apprehending Beauty as a Form involves the love of Love itself, rather than the desire for any one thing or person. Ascent up the ladder of love entails a move from the senses to the intellect. The apprehension of Beauty is therefore an intellectual act, not the product of an overpowering emotion, as in the case of eros.

Diotima is certain that if Socrates ever manages to reach the highest rung of the ladder of love—that is, if he apprehends the Form of Beauty—then he will never again be seduced by the physical attractions of beautiful individuals. In other words, having apprehended Beauty in its highest form—the intellectual love of Love—he will never again experience eros.

The ladder of love parallels the allegory of the cave in that it represents an ascent by the philosopher from a state of ignorance to an apprehension of what is ultimately real.