Many interpreters of Plato held that his writings contain passages with double meanings, called allegories, symbols, or myths, that give the dialogues layers of figurative meaning in addition to their usual literal meaning. These allegorical interpretations of Plato were dominant for more than fifteen hundred years, from about the 1st century CE through the Renaissance and into the 18th century, and were advocated by major Platonist philosophers such as Plotinus, Porphyry, Syrianus, Proclus, and Marsilio Ficino. Beginning with Philo of Alexandria, these views influenced the Jewish, Christian, and Islamic interpretation of these religions' respective sacred scriptures. They spread widely during the Renaissance and contributed to the fashion for allegory among poets such as Dante Alighieri, Edmund Spenser, and William Shakespeare.

As a literary device or artistic form, an allegory is a narrative or visual representation in which a character, place, or event can be interpreted to represent a meaning with moral or political significance. Authors have used allegory throughout history in all forms of art to illustrate or convey complex ideas and concepts in ways that are comprehensible or striking to its viewers, readers, or listeners.