00:00:00.000 Mistakes are ubiquitous, error is always with us, the whole purpose of creating knowledge
00:00:06.480 is to correct errors, we cannot have certainty about anything ever.
00:00:11.520 But at the same time, this does not mean that all claims to truth are on equal footing.
00:00:16.760 Relativeism, the idea that all claims to truth are equal, that everyone's opinion
00:00:22.560 This false science, mathematics, philosophy and morality uncover objective truth about reality.
00:00:31.640 If something is objectively true, this does not mean it is certainly true.
00:00:48.920 It's a feeling you get, or at least a feeling some people seem to want to have.
00:00:54.440 The feeling that you are definitely without a doubt correct is no guarantee that you are.
00:01:02.560 Someone without doubt is dogmatic, and dogmatism only ever leads to evil.
00:01:07.720 Do you remember the time when you were certain that through any two points, only a single
00:01:17.600 Perhaps you still are depending upon how much maths you remember.
00:01:23.080 There are two random points and you are on a piece of paper.
00:01:26.440 And draw a straight line through those two points.
00:01:29.960 Can you draw more than one line through those two points?
00:01:37.680 It said only one line can be drawn through those two points.
00:01:40.960 Indeed, Euclid, who first laid down our mathematical foundations of geometry, provided
00:01:49.720 And this is what you are taught in school geometry class.
00:01:57.920 Most people are certain at least for some time that only one such straight line can be
00:02:09.840 Suddenly infinitely more straight lines can be drawn.
00:02:13.600 Your prior certainty is undermined by a simple change of perspective.
00:02:30.520 Did you misunderstand the instruction as I first posed it to draw a straight line through
00:02:37.320 Could I have phrased it in such a way as to not be misunderstood by you?
00:02:41.800 Carl Popper once said, it is impossible to speak in such a way that you cannot be misunderstood.
00:02:55.000 So when someone says, I know X, where X is any claim at all.
00:03:00.120 What they're not in actuality saying is, I am certain that X is the case.
00:03:04.960 Or even I am justified in believing that X, no.
00:03:09.480 What they actually mean is, the best idea I have at the moment is X and I've got no
00:03:15.680 When people say they know X, they're not saying they can't actually change their
00:03:20.800 Yes, of course, some people are dogmatists and claim not to doubt X when X is either something
00:03:25.320 really obvious or something that is really important to them.
00:03:28.440 But they're thinking these things does not change the true structure of knowledge, or
00:03:32.480 that they are, in fact, actually, fallible humans.
00:03:36.720 We should know that even if they claim to have no doubts, we should doubt that very
00:03:41.680 Or better yet, understand that if they thought better about things, then they would
00:03:45.200 like us, understand that although knowledge is genuinely possible, the feeling that one
00:03:49.880 is certain is no guarantee at all, that one is in possession of the final ultimate truth.
00:03:54.880 That final ultimate truth is something we aim for, but it's not something we can ever
00:04:02.320 The justified true belief mistake handed down to us from Plato remains deeply ingrained
00:04:07.320 in our language and ways of thinking about knowledge.
00:04:10.840 So it's just that a mistake, knowledge isn't anything to do with being justified true,
00:04:16.400 which is to say in some way finally shown to be not possibly false.
00:04:20.720 Or even about the beliefs of people, knowledge instead is very much a real thing, abstract,
00:04:29.880 In other words, physical structures are arranged in particular ways in order to code the
00:04:35.480 So, for example, brains in code knowledge, but so too do computers and even telescopes.
00:04:41.000 All these structures encode causal relationships between objects so that something useful
00:04:46.040 can be done with the information, pop or understood, that knowledge is real and possible.
00:04:51.200 But many people think he rejected knowledge because they think his entire philosophy is
00:04:57.800 So they think pop is philosophy says something like, you can be sure about those things
00:05:01.680 who are falsified, but not about anything else or something like that, but this is one
00:05:06.000 of them are completely, pop it did not think you could be sure, as in certain or absolutely
00:05:10.000 100% without any doubts for all time satisfied, that anything was true, or false, no.
00:05:19.320 Everything we know is always conjectural, which is to say tentative.
00:05:23.840 It contains truth, but it's not the final truth.
00:05:27.400 Such claims are explanations about what is true, falsification, or refutation more broadly,
00:05:33.440 rules out some explanations, theories, ideas, hypotheses, as being good explanations.
00:05:39.560 David Deutsch sharpened up this idea even more, an experimental refutation makes a theory
00:05:44.200 almost impossible to vary in such a way as to account for the refutation.
00:05:49.520 In other words, if your favourite beautiful theory is slain by an ugly fact, then if the
00:05:54.280 theory is any good, you shouldn't be able to change it just a little bit in order to now
00:06:00.840 If you think eating a kilogram of grass cures the common cold, and someone tries and it
00:06:06.120 doesn't work, so your theory is falsified, then if you come back with, oh actually it's
00:06:10.640 probably more like 1.1 kilograms, let's try again.
00:06:14.480 This is called an ad hoc modification, making your theory easy to vary, and so we can reject
00:06:21.640 the grass cures the cold theory, and all infinite variants of it on that basis.
00:06:26.960 We don't have to keep testing it, and it's fair for us to say, we know that grass doesn't
00:06:35.560 That we're certain one day someone won't come along and show how if you isolate some
00:06:39.640 chemical in grass and add it to some other chemical in alcohol and take it as a pill
00:06:45.960 No, we can never be sure, but we've no reason whatever to think that this is, or ever
00:06:53.920 Popper was never a skeptic in the philosophical sense of the word, quite the opposite.
00:06:58.440 Skeptics believe in the justified true belief theory of knowledge, they rightly conclude
00:07:02.760 one can never be absolutely certain about knowledge claims, but then wrongly conclude,
00:07:09.560 Popper was a critic of this idea, he rejected it completely, he threw it away, root and branch
00:07:14.000 and started from the ground up, the idea here is to divorce knowledge from being about
00:07:18.120 certainties or justified truth, instead knowledge is possible because there is an objective
00:07:25.400 None of them are final absolutes, but in almost all cases, always where there are two or
00:07:30.320 more competing claims, one of them is better than the other.
00:07:33.920 The process of criticism rules out all, but one of the ideas, ideally, over the one
00:07:39.640 that survives, we say, I know that, that claim comes to be called part of our knowledge
00:07:49.200 Popper was no skeptic about knowledge, he was a critic and these are quite different things.
00:07:53.680 One of them assumes knowledge is not possible, because certainty isn't.
00:07:57.400 The other, the critical idea, says almost exactly the opposite, the pursuit of knowledge
00:08:01.880 and its objective growth and improvement is only possible because certainty is not.
00:08:06.520 To unpack this a little more, if we were able to be certain, then this would mean we'd
00:08:11.440 have direct access to final truth and this would mean the quest for knowledge would stop.
00:08:16.400 We'd just tap into that ultimate source of truth and that would be that, game over.
00:08:21.120 We'd never improve anything because we'd have the final complete answer and all the answers.
00:08:26.440 So the pursuit of knowledge would stop, but happily, the pursuit of knowledge isn't like
00:08:30.240 this at all, knowledge is hard one and it comes to us with much misconception.
00:08:35.320 Almost all we know contains misconception and we can never be sure which is misconception
00:08:43.920 As long as our process of error correction keeps on sifting the misconceptions from the
00:08:48.120 kernels of truth so that we make progress this is all we need to be able to say we are
00:08:53.320 creating knowledge or we are learning and making objective progress.
00:08:57.680 We can't know we've got the final truth ever, but what we can know is that our process
00:09:02.640 of criticism, experimental force of occasion and other kinds of refutation make the ideas
00:09:08.160 that survive this process objectively better than the ideas that do not.
00:09:13.560 The purpose of science is to correct our knowledge about physical reality.
00:09:16.880 Here we see improvements most obviously perhaps, objective progress seems to be made all
00:09:22.600 New medical discoveries improve our health and lengthen our lives and cure disease previously
00:09:27.640 Each new iPhone is better than the one that went before and each new car engine is more
00:09:34.040 One great theory is overturned by another even better theory, new explanations for a place
00:09:39.240 The new ones are not certainly true, but just closer to the so-called ontological truth
00:09:48.480 This means closeness to truth whereby truth we mean ontological truth.
00:09:55.080 Ontological truth is a description of what is really there.
00:09:58.600 We do not have a method for finding a final once and for all description of what is really
00:10:05.600 It means that the quest for knowledge is infinite.
00:10:10.480 We don't find a final fact about reality and just stop and say, well that's it.
00:10:17.080 We now know everything there is to know about this.
00:10:24.560 This means we must try to show which of our ideas are wrong and how.
00:10:28.720 And so this is the best thing you can do to help progress along.
00:10:31.680 You don't need to be a great philosopher, a quick thinking mathematician or a creative scientist.
00:10:38.440 Critics have a bad reputation and they don't deserve it.
00:10:40.840 There are two equally important ways to be in the world when it comes to progress.
00:10:48.440 All of these at various times and both are absolutely essential to creating knowledge.
00:10:53.080 Creation can result in improvements and that's great.
00:10:55.760 Producing something new can be exhilarating, but that again is just a feeling just because
00:11:01.640 Doesn't mean you've actually produced something of value.
00:11:05.840 You might very well be right about your new creation.
00:11:10.040 Your new idea will spread some new art more beautiful or more incisive might make you
00:11:15.240 Some new scientific theory to overturn an old theory could solve a problem previously
00:11:19.440 a stumbling block to progress might even improve the world.
00:11:22.440 But sometimes new creations that lead to dead ends.
00:11:28.120 Having stuff that doesn't do what you wanted to, art that's just not good, music no
00:11:33.640 A painting everyone says is derivative of a scientific theory quickly slain by an experiment
00:11:38.160 that shows it to be wrong, a computer game no one wants to play.
00:11:42.480 Criticism is how we sift the good, the beautiful, the true, the useful, from the bad,
00:11:50.720 And this is true for ideas generally and for your own ideas personally.
00:11:56.160 And don't be upset when others criticize your ideas, they're not criticizing you personally.
00:12:04.240 You can discard ideas and you can criticize the criticisms, you can defend your ideas.
00:12:09.600 If you want to get better, as fast as possible, create, criticize and repeat.
