WEBVTT

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What is reality, knowledge,
the meaning of life?

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Big topics you might tackle figuratively

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explaining existence as a journey 
down a road or across an ocean,

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a climb, a war, a book, a thread, a game,
a window of opportunity,

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or an all-too-short-lived 
flicker of flame.

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2,400 years ago,

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one of history's famous thinkers said
life is like being chained up in a cave,

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forced to watch shadows 
flitting across a stone wall.

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Pretty cheery, right?

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That's actually what Plato suggested
in his Allegory of the Cave,

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found in Book VII of "The Republic,"

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in which the Greek philosopher
envisioned the ideal society

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by examining concepts 
like justice, truth and beauty.

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In the allegory, a group of prisoners
have been confined in a cavern since birth,

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with no knowledge of the outside world.

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They are chained, facing a wall,
unable to turn their heads,

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while a fire behind them
gives off a faint light.

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Occasionally, people pass by the fire,

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carrying figures of animals and other objects
that cast shadows on the wall.

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The prisoners name 
and classify these illusions,

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believing they're perceiving
actual entities.

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Suddenly, one prisoner is freed
and brought outside for the first time.

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The sunlight hurts his eyes and he finds
the new environment disorienting.

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When told that the things 
around him are real,`

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while the shadows were mere reflections,
he cannot believe it.

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The shadows appeared much clearer to him.

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But gradually, his eyes adjust

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until he can look 
at reflections in the water,

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at objects directly,

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and finally at the Sun,

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whose light is the ultimate source
of everything he has seen.

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The prisoner returns to the cave
to share his discovery,

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but he is no longer used to the darkness,

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and has a hard time 
seeing the shadows on the wall.

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The other prisoners think the journey
has made him stupid and blind,

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and violently resist 
any attempts to free them.

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Plato introduces this passage
as an analogy

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of what it's like to be a philosopher
trying to educate the public.

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Most people are not just comfortable
in their ignorance

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but hostile to anyone who points it out.

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In fact, the real life Socrates
was sentenced to death

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by the Athenian government 
for disrupting the social order,

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and his student Plato 
spends much of "The Republic"

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disparaging Athenian democracy,

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while promoting rule by philosopher kings.

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With the cave parable,

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Plato may be arguing that the masses
are too stubborn and ignorant

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to govern themselves.

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But the allegory has captured
imaginations for 2,400 years

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because it can be read in far more ways.

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Importantly, the allegory is connected
to the theory of forms,

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developed in Plato's other dialogues,

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which holds that 
like the shadows on the wall,

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things in the physical world are flawed
reflections of ideal forms,

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such as roundness, or beauty.

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In this way, the cave leads to many
fundamental questions,

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including the origin of knowledge,

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the problem of representation,

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and the nature of reality itself.

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For theologians, the ideal forms
exist in the mind of a creator.

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For philosophers of language
viewing the forms as linguistic concepts,

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the theory illustrates the problem
of grouping concrete things

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under abstract terms.

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And others still wonder whether
we can really know

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that the things outside the cave
are any more real than the shadows.

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As we go about our lives,

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can we be confident 
in what we think we know?

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Perhaps one day,

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a glimmer of light may punch a hole
in your most basic assumptions.

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Will you break free to struggle
towards the light,

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even if it costs you 
your friends and family,

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or stick with comfortable
and familiar illusions?

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Truth or habit? Light or shadow?

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Hard choices, but if it's any consolation,
you're not alone.

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There are lots of us down here.