0:00 From the ancient Greek skeptics all the way to modern neuroscientists, the simple question of what it means to truly 'know' something has been this relentless, unwinnable intellectual battle.0:17 Right.0:18 And last week we were talking about wrestling with these big philosophical dilemmas, and this… this feels like the one that sits underneath ALL of them.0:32 Exactly.0:32 The whole project of trying to figure things out depends on the idea that we can figure things out.0:42 But can we?0:43 Like, can we ever truly, one-hundred-percent know anything for certain?0:49 Oh, that’s the deep end right away.0:52 I mean, my first instinct is to say, "Of course." I know the sky is blue.0:59 I know I'm talking to you right now.1:03 That's empiricism, right?1:05 I know what my senses tell me.1:08 See, I want to agree.1:10 But then I think about optical illusions, or how a stick looks bent in water.1:17 My senses can be fooled.1:19 They ARE fooled, all the time.1:22 So if the foundation is shaky, how can I trust the building?1:27 Mm-hm.1:28 Okay, so the senses are fallible.1:31 The rationalists would say that's why you can't rely on them.1:36 Real knowledge comes from reason, from logic.1:41 Like, I know that two plus two equals four, not because I saw it somewhere, but because I can deduce it logically.1:51 It HAS to be true.1:53 I get that for math.1:55 But what about… love?1:57 Or justice?1:58 Or knowing who you are?2:00 You can't just use a formula for that.2:03 And even with logic, you're starting from axioms, from assumptions you have to accept without proof.2:12 You’re just a full-blown skeptic today, aren't you?2:17 You're channeling Pyrrho of Elis, just walking around saying, "I suspend judgment on that." Maybe I am!2:27 But it's a genuine problem.2:29 Take science.2:30 We talk about scientific knowledge.2:34 But what is that, really?2:36 It’s just the best model we have right now, based on the evidence available.2:43 And we know it's going to be revised, or maybe even thrown out completely in a hundred years.2:52 But that's the strength of it!2:54 The fact that it's revisable is what makes it work.2:59 It's a process of getting less wrong over time.3:03 It's not about absolute certainty, it's about having a belief that is justified by evidence.3:12 A justified belief… but is that the same as knowing?3:17 I can have a justified belief that my car is where I parked it.3:22 The evidence is: I parked it there, no one has a key, it's a safe neighborhood.3:30 But it could have been stolen.3:33 Or towed.3:33 I don't actually KNOW it's there until I see it.3:38 So for you, knowledge requires the elimination of ALL doubt?3:43 Even the most absurd, "what if a meteorite hit JUST my car" kind of doubt?3:50 Well, that’s the question, isn't it?3:54 Where do you draw the line?3:56 Because once you admit a little bit of doubt is acceptable, how do you stop the whole thing from unraveling?4:06 What if this is all a dream?4:09 Or a simulation?4:10 The brain in a vat.4:12 Yeah.4:12 And the hard thing is, there's no argument that can prove you're NOT a brain in a vat.4:20 Any piece of evidence you point to, any sensation… could just be part of the simulation.4:28 It's a perfect, inescapable trap.4:31 And it makes me wonder if we're even asking the right question.4:37 Maybe the goal isn't to arrive at this final, static thing called "knowledge." Maybe the value is in the questioning itself.4:49 In holding our beliefs lightly.4:52 In being open to being wrong.4:54 It's… um, it's a more humble way of being in the world, I guess.5:00 Yeah.5:01 It replaces the arrogance of certainty with the curiosity of doubt.5:07 You stop trying to have all the answers, and you get better at asking questions.5:14 And maybe that's a kind of knowledge, too.5:18 Knowing the limits of what you can know.5:22 So we can't ever truly know anything… except, perhaps, for the fact that we can't ever truly know anything.5:32 Now you're just trying to give me a headache.5:36 But yeah.5:37 Something like that.
