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My name is Jennifer Nagel.
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I teach philosophy at the university of Toronto,
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and today I want to talk to you about knowledge.
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Knowledge is something human beings naturally crave,
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we spend a lot of time and effort
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trying to gain it, for example by
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watching videos like this one.
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We also have natural instincts to keep
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track of what other people do and don't know
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in order to make sense of what they're doing.
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But it's suprisingly difficult to give a good
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explanation of the nature of knowledge itself,
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and to say how knowing that something is
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true, differs from just thinking that it's true.
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When we try to figure out what knowledge is,
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we encounter some interesting questions
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and paradoxes. This series explores these problems,
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and explains how philosophers have tried to solve them.
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This particular video will focus on some basic
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features of knowledge, features that any good
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theory of it should try to explain.
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So, what kinds of things can you know?
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The english verb "know" is used in several ways;
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you can know a person, "Alice knows Pierre";
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a place, "Pierre knows Paris";
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or a language, "Alice knows french".
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But the most common way of using the verb
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"to know" is the way we use it when we're
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speaking of someone knowing a fact, as in
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"Alice knows that it's raining outside".
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In this series we'll be focusing on this
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knowing-a-fact sense of the verb "to know".
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Sometimes this is called "knowledge-that",
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but actually, along with "that", you can use
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question words like "where" or "when".
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"Pierre knows when the party will start"
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or "Pierre knows where the party is".
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Knowing where the party is means knowing the
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answer to the question "where's the party?",
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and that's going to be a fact, like the fact
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that the party is at Alice's place. Knowledge is
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a way of being latched on to a fact.
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It is thought that every language in the world
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has a word that works to translate this fact-grabbing
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sense of the word "to know".
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And this kind of global popularity is very rare,
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only about a hundred words are thought
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to be universal in this way.
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Around the world, words meaning "to know" are
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also very heavily used. It's one of the top ten
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most common words in english for example.
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So we often find ourselves talking about
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knowledge, but when we say someone knows
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something, what do we mean?
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It can help to compare knowing and just believing.
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Consider these two sentences:
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1. "Alice knows that it's raining outside."
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2. "Pierre believes that it's raining outside."
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We instinctively feel some difference between
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Alice and Pierre, but what is it?
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Actually, we'll see there's several possible
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points of contrast here.
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The first and easiest has to do with truth.
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If Pierre just believes that it's raining outside,
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where he is, maybe he's wrong. Maybe the
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rain has stopped, and he's fooled by the
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sound of water dripping from the trees.
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The things we believe are sometimes true
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and sometimes false.
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What we actually know on the other hand,
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has to be true, or factual. So there's no problem saying
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"Pierre believes it's raining, but it isn't."
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While it sounds weird to say
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"Alice knows it's raining, but it isn't."
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This is because attachment to the truth
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is built into the meaning of knows-that.
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Beyond truth, another key feature of
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knowledge is confidence.
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Let's suppose that Pierre is in a windowless
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room, and he's been there for an hour.
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He could suspect that it's still raining
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outside, even of he's not totally sure.
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But if Alice knows that it's raining, she has
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no doubt. She's confident.
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So, is confident belief in a truth enough
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for knowing? Apparently not.
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There's at least one more thing we need.
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Imagine that Pierre is really pessimistic,
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he's always strongly convinced that
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things will go badly. He's often wrong,
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but sometimes he's right. Today he wakes up
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in a windowless room, aware that Alice has
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planned a picnic because the forecast was
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for sunny weather. "It's going to be terrible",
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he thinks. "I'm sure it's already raining right now".
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He's entirely confident that it's raining,
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although he can't actually see or hear the rain.
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And let's say by chance it turns out he's
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right this time. Does Pierre actually know
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that it's raining outside?
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If he doesn't know, then it seems knowledge
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requires something more than confident
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belief in a truth. Feeling pessimistic isn't
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a good basis for judgements about the weather.
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Your judgement needs to have a good basis
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in order to count as knowledge.
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But what kind of basis counts as good?
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Do you have to be standing outside,
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getting wet? As you will see,
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in the upcoming videos on the analysis of
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knowledge, this is a controversial question.
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But before we get to that problem, we'll
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tackle a more basic problem: is knowledge even
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possible for us? Even in the best case
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scenario, when it feels like you're standing
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right outside, right in the rain, can you
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really know that it's raining outside?
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Could you be dreaming for example,
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on a clear night?
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This is the problem of skepticism,
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explored in the next video.
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The two following videos will explain
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possible solutions to skepticism.