How do you acquire knowledge? There are lots of things you think you know; but how did
you get to know them? Seems like kindof an important question: after all, if a dodgy
email scammer told you they could for definite make you a millionaire overnight if you just give them
your bank details, you might be a little sceptical. Where you get your information really matters.
In the 18th Century, there were two camps of philosophers. On one side you had the Empiricists,
who thought that if you want to get knowledge you have to experience the world. If you want
to know how big elephants are or how hot the Sun is, you have to go and check. Maybe do
an experiment or take a measurement.
On the other side you had the Rationalists, who thought that the only way to get real
knowledge was to figure it out. You can know without doing any kind of experiment that
2 and 2 makes 4, and that all bachelors are unmarried. Those things are certain. Those
are the sorts of things the rationalists thought were knowledge. Their reasoning was that your
senses can deceive you: if you do an experiment or take a measurement, you could be hallucinating,
or you could have got it wrong. That's why they thought real knowledge had to have the
kind of certainty that these ideas do.
Into the middle of this debate between the rationalists and the empiricists came Immanuel
Kant, who kindof took a middle road. Kant thought that there were some concepts you have
in your head, that you couldn't have got by experiencing the world. But you also couldn't have just sat down and
figured them out either.
Take the concept of space, for instance, as in distance between objects. You rely on that concept
a lot when you're walking around the world. Imagine a baby experiencing space for the first time:
they couldn't go, "Oh that object is over there and I'm over here so there must
be space in between!" because in order to say, "That obect is over there," you must
already have the concept of space in your head! You couldn't have goten it by
experiencing the world.
But at the same time you couldn't have just sat down and figured it out either: it's not like '2+2 is 4' or 'all bachelors are unmarried,'
there's nothing definitionally true about space.
So what Kant realised was that some concepts like space - he also included
number and time - must be built into us from the beginning. Our brains must be hard-wired
to experience the world in that way. As soon as the baby is experiencing anything, they're
experiencing it spatially. These synthetic a priori concepts, as he called
them, must be a condition of having a mind. All minds have them.
This all might seem a little bit overwhelming and technical, so I like to explain it using Pokémon. You can go out
into the world and capture new knowledge - you can experience
food and music and love, and gain knowledge about those things. But you always get a starter Pokémon and a few Pokéballs
to get you on your way, and you can't begin your journey towards being a Pokémon Master until you've
picked your starter. So your synthetic a priori concepts are like your started Pokémon.
This is called a "Transcendental Argument." Now Kant loves to throw around the word "Transcendental"
but don't be scared of it: a Transcendental argument is when we say, "OK, we do things
like this, so whatever the background conditions are that are necessary for us to do those
things, they conditons must be true. "Transcendent" in this case just means "going beyond what
we have in front of us."
So, Kant thought that some concepts like space and time were built into you as a condition of having a mind, and we have to experience the world like that. But,
and go with me here, if you have to experience he world in those ways, then how do you know that
the world is really like that? Your synthetic a priori concepts are like a pair of glasses
you can never take off, so how do you know that space and time and all that are really part of the
world, and not just in your head? What would the world of Pokémon be like if you never became a Pokémon
trainer; you just experienced it directly?
And this leads us to one of Kant's most famous and important bits of philosophy. He
takes the whole world and divides it into two halves: on one hand you've got the world as we experience it; he
called that the phenomenal world. But on the other hand you've got the world as it is in itself, independent of
anybody's experience. He called that the noumenal world, and we can never experience the noumenal world, because
as soon as you experience something it's part of the phenomenal world. The noumenal
world might not have space, and time, and all the things that are so fundamental
to the way we experience the phenomenal world. It might have 'em. But it might not.
This distinction between the noumenal and the phenomenal world is the key to understanding so
much of Kant's work, particularly what he had to say about free will and God,
which, don't worry, I won't bother you with that today. So just remember: certain ways
of obtaining knowledge are built into you. So knowledge is as much a feature of you as
it is a representation of the world
What do you think? Do human beings have synthetic a priori concepts? Leave me a comment
telling me what you thought, and for more philosophical videos, don't forget to subscribe.
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This episode was filmed in YouTube Space London as part of YouTube's NextUp Creator Camp!
Massive thank you to Phil from the Phil Green Show, to Maggie from RedTed Art, and to BirdKeeper Toby for being in it with me: you can find links to all of their channels below.