“Reality,” wrote Philip K. Dick, “is that which, when you stop believing in it, doesn’t go away.” And yet how are we to be sure that what we observe actually is? After all, so much of what we experience as reality is the product of our remarkably flawed perception.

Some 2,400 years earlier, Plato explored this very question in his famous Allegory of the Cave — perhaps history’s most masterful figurative inquiry into the meaning of life and the nature of reality — found in Book VII of his Republic (free download | public library).

From my friends at TED-Ed — who have previously given us wonderful animated distillations of why we love repetition in music, how to detect lying, why bees build perfect hexagons, and how melancholy enhances our creativity — comes this elegant synthesis of Plato’s famous parable, its enduring wisdom, and how it illuminates some of the most fundamental questions about the human experience, from the origin of knowledge to the essence of reality itself.

Most people are not just comfortable in their ignorance, but hostile to anyone who points it out.

Complement with Alan Watts on what reality is and Nobel-winning psychologist Daniel Kahneman on how our minds mislead us.