Lifetimes of Learning

If you’re like anything the typical philosopher, your response to the title of this week’s episode may be, “How do we learn what?” After all, among the things you may have learned are (1) facts, (2) things that happened, and (3) skills. You might know that pastries are delicious; you might know that you went to Paris last month and ate pastries; and you might know how to order those pastries in French. All of these are different kinds of knowledge that presumably require different kinds of learning.

Start with the tasty part: how do you learn that pastries are delicious? The obvious answer is from your senses: you put one in your mouth and notice that It’s sweet and warm and melty. You learn what a pastry is, what sweetness is, maybe even how good it is be alive in a world with such deliciousness. Some would say it’s the way you learn anything: you gather information from the world via your senses. As empiricists liked to say, “There’s nothing in the mind that wasn’t first in the senses.”

But you can also learn from testimony—from someone else telling you something—which may be a whole lot better. After all, you could learn that fire is hot by sticking your hand into one, but take someone else’s word for it is probably safer. Of course, if your sister-in-law is constantly telling you that swimming is deathly dangerous and you should give up scuba-diving immediately, surely you shouldn’t trust that bit of testimony: if you really want to be sure what something is like, you have to go out and learn it yourself using those wonderful senses of yours, which tell you how amazing the ocean is.

But we can also learn about plenty of things we can’t see or touch or taste. Eating that delicious pastry, for example, caused you to feel happy. But how did you know what a cause is? Your senses can tell you what a pastry is and what sweetness is, but they can’t tell you what a cause or an effect is. Philosophers like Immanuel Kant say we don’t get that knowledge from anywhere; instead it’s in our brains from the outset. When we’re born, we don’t have any information about specific things in the world, like delicious pastries or hot fires or beautiful oceans—but we do already have a kind of pre-programming that leads us to expect things to cause other things.

After all, it can sound a little magical to ask a brain that doesn’t have anything in it to just start taking in a bunch of data from the world, think about it a bit, and draw conclusions. If our minds didn’t have the capacity to organize experience, everything would be total chaos. We wouldn’t be able to learn anything about pastries, because we wouldn’t even be able to single out pastries from the giant mess that would constantly be bombarding our senses. It’s lucky for us that we have the brains we do, so that we can learn what causes happiness. (Answer: French pastries.)

But then again… suppose one day all the pastries in the world start tasting like cilantro, and you’re one of the unfortunate few for whom cilantro takes like soap. If that happens, you’ll realize that you were totally wrong about pastries. You just happened to have eaten a few hundred that tasted delicious, and your mind jumped to the conclusion that all pastries must be delicious. You thought you were getting reliable knowledge, but you weren’t. So what have you learned about the world? We clearly need to know more about how learning works, and we’ll learn that from our guest: it’s Catherine Hartley, Professor of Psychology and Neural Science at NYU, where she studies learning in her lab.