2012: Advent Philosophy: Gettier Counter-Examples

by on December 4, 2012

Yesterday, I covered what most epistemologists think “knowledge” is: Justified, True Belief. (Or just JTB for short.)

Today, I’m going to tell you about Gettier, who is a massive troll, and incredibly lazy, successful philosopher. Everything I want to be when I grow up.

Troll

For those of you who don’t know, American education is run on a tenure system. If you get tenure, you’re set for life, but in order to get it you need to have some respected publications under your belt. Gettier was a philosophy professor who needed tenure but had published very little. So he wrote two pages which blew the Justified True Belief theory out of the water, completely screwed up the entire field of Epistemology, got tenure, and never published again. Massive troll, right?

He did this by thinking up some situations in which a person has Justified True Belief, but it still seems intuitively wrong to say that they have knowledge. There are lots of examples, but the interesting thing is that they actually turn up in books pretty often. They make great plot twists! There are examples from Shakespeare and from Agatha Christie… but more importantly, there is an example from Harry Potter. Oh yes.

Hey I never noticed they put runes in the mugshot ID number. That is pretty cool.

Spoiler Alert!

This is Harry’s godfather, Sirius. Harry doesn’t find out Sirius exists until a couple years into school, because Sirius is a Notorious Mass-Murderer who everyone thinks is responsible for the death of Harry’s parents. Harry overhears his teachers talking about how tragic it is: Sirius was James Potter’s best friend, he was magically protecting the Potters’ home, but then he betrayed them and caused them to be killed by Voldemort. Harry is, obviously, traumatized.

You can tell he’s angsty because you can only see half his face.

So let’s pause to take a peek into Harry’s mind right now, examine what he knows.

Harry’s Knowledge: My godfather is responsible for the death of my parents! Noooooooo!

  • Justification: Harry overheard his teachers (and the Minister of Magic, and a sexy barmaid who makes delicious mead) talking about this.
  • Belief: These are some pretty decent authority figures, and they’re not mincing words because they don’t know Harry is listening. Not surprisingly, he believes them.
  • Truth: It is actually true that Harry’s godfather is responsible for the death of his parents. Stay with me, Potter fans. Here comes the plot twist, right?

After many chapters of angst, Harry finally finds Sirius and confronts him at wand-point about the death of his parents. Sirius confesses responsiblity for the death of Harry’s parents. He completely blames himself. But it didn’t happen like Harry (and the rest of the world) thinks it did. Sirius was going to be the person magically protecting the Potters’ house, but instead he gave the responsibility to their other friend, Peter. Peter then ran off and told Voldemort where Harry’s parents were. Peter was always a snivelly git, and Sirius is tortured over his complete lack of good judgement, which got his best friend killed and orphaned Harry.

image

You can tell he’s evil, because he looks weird.

In the end Harry doesn’t really blame Sirius for this. In fact, the only person who really blames Sirius for this is Sirius. (And me. Come on, you hippies.) But, nevertheless, everything that was stated above is still accurate:

Harry’s Knowledge: My godfather is responsible for the death of my parents! Noooooooo!

  • Justification: Harry overheard his teachers talking about this. (But they didn’t have the full story.)
  • Belief: These are some pretty decent authority figures, and they’re not mincing words because they don’t know Harry is listening. Not surprisingly, he believed them. (But now he knows more, too.)
  • Truth: It is actually true that Harry’s godfather is responsible for the death of his parents. (But Harry is a nice guy who doesn’t hold it against Sirius.)

 This is what we call a Gettier Counter-Example. By the JTB theory, he knows something. He believes it, he has good reason to believe it, and it’s true. But it still seems off, right? Technically, maybe, it fits the definition. But it’s missing a big part of the picture. The fact that Harry knows this thing seems to have come down to luck, somehow.

And thus, all the epistemologists are fooked. They have this nice definition and yet it can still come down to luck! Gee, thanks, Gettier.

There are a whole bunch of proposed solutions, and none of them are really agreed upon yet, even though they’ve been yelling about this for more than 40 years now. (While Gettier has enjoyed quietly lecturing and mostly ignoring all the discourse he caused.) I’m going to move on to other Philosophy topics rather than subject you to yet more of this, but if you’re interested, I recommend picking up a copy of “What is this thing called Knowledge?” which is very clearly written and accessible.

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