BCE = 380 BCE Plato wrote The Allegory of the Cave in about 375 BCE. It is one of his most famous works and has had a considerable influence on Western philosophy, especially on Aristotle and Augustine. Plato used the story to explain how humans come to know anything real. In fact, the story can be found in several of his other books including Critias, Cratylus, and Theaetetus. It is also mentioned by name in Letters from Athens by Plutarch who discussed it in detail along with many other Greek philosophers. This means that The Allegory of the Cave was already well-known when Augustine wrote about it in Book XI of The City of God in 400 CE. Augustine used the story to argue that only knowledge derived from faith in Christ can lead us to true happiness. This shows that Plato was not the first writer to use the story; he simply gave it new life by applying it to reality instead of just imagining it.