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