WEBVTT

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How do you know you're real?

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It's an obvious question
until you try to answer it,

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but let's take it seriously.

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How do you really know you exist?

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In his "Meditations on First Philosophy,"

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René Descartes tried to answer
that very question,

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demolishing all his preconceived
notions and opinions

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to begin again from the foundations.

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All his knowledge had come
from his sensory perceptions of the world.

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Same as you, right?

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You know you're watching this video
with your eyes, hearing it with your ears.

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Your senses show you the world as it is.

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They aren't deceiving you,
but sometimes they do.

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You might mistake a person
far away for someone else,

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or you're sure you're about
to catch a flyball,

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and it hits the ground in front of you.

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But come on, right here and now,

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you know what's right
in front of you is real.

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Your eyes, your hands,
your body: that's you.

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Only crazy people would deny that,
and you know you're not crazy.

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Anyone who'd doubt that must be dreaming.

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Oh no, what if you're dreaming?

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Dreams feel real.

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You can believe you're swimming, flying

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or fighting off monsters
with your bare hands,

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when your real body is lying in bed.

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No, no, no.

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When you're awake, you know you're awake.

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Ah! But when you aren't,
you don't know you aren't,

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so you can't prove you aren't dreaming.

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Maybe the body you perceive
yourself to have isn't really there.

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Maybe all of reality,
even its abstract concepts,

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like time, shape, color
and number are false,

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all just deceptions concocted

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by an evil genius!

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No, seriously.

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Descartes asks if you can disprove
the idea that an evil genius demon

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has tricked you into
believing reality is real.

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Perhaps this diabolical
deceiver has duped you.

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The world, your perceptions
of it, your very body.

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You can't disprove
that they're all just made up,

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and how could you exist without them?

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You couldn't! So, you don't.

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Life is but a dream,

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and I bet you aren't row, row,
rowing the boat merrily at all, are you?

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No, you're rowing it wearily

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like the duped, nonexistent
doof you are/aren't.

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Do you find that convincing?

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Are you persuaded?

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If you aren't, good;
if you are, even better,

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because by being persuaded,

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you would prove
that you're a persuaded being.

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You can't be nothing
if you think you're something,

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even if you think
that something is nothing

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because no matter what you think,
you're a thinking thing,

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or as Descartes put it,
"I think, therefore I am,"

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and so are you, really.

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(Airplane engine)