0:07 okay so it's going to be two to two
0:08 parts and they're to two different
0:10 lectures so in the first part I'm
0:13 primarily talking about arguments for
0:14 the non existence of the external world
0:16 and then after the break in the second
0:19 part we are going to look at the whole
0:21 thing in a bit more abstract manner
0:23 asking whether there can be any
0:25 ultimately true theories of reality at
0:29 all and just as the spoiler alert the
0:32 answer to both is going to be no okay so
0:34 if you don't want to know the arguments
0:35 you can leave now all right because you
0:36 know what though it's all going to end
0:39 so okay so let's let's get started so
0:44 when we are talking about denying the
0:47 existence of the external world
0:49 I should probably first of all tell you
0:50 roughly what at what I mean by that so I
0:52 don't mean a kind of Barclays and
0:55 idealism which that says all things are
0:58 ornamental so there really no physical
1:01 objects and it's only the case that we
1:03 mistake mental objects for physical
1:05 objects right so that's that's not that
1:07 what I mean by denial of an of an
1:10 external world so I'm interested in the
1:14 more general denial of objects that
1:16 exist independently of human interest
1:18 sense concerns whether such objects are
1:21 tables or chairs or in Buckley's case
1:23 that divine ideas right so for somebody
1:26 like Berkeley there would be an external
1:27 world it's just an external what is
1:30 mental yeah and for for therefore your
1:32 standard to sentient materialist there's
1:33 an external what the external world is
1:36 material yeah but what I'm interested in
1:37 is actually a theory that tries to
1:39 undercut the fundamental assumption that
1:40 there is some stuff that exists
1:44 independently of us independently of our
1:46 interests and concerns whether that
1:52 stuff is mental or physical now the the
1:56 question that I get often asked in this
1:57 context when I when I when I talk about
2:00 this idea is whether my position is a
2:03 kind of ontological agnosticism or is it
2:05 ontological atheism right so let me just
2:09 explain what I mean by that and so on
2:12 geological agnosticism would just be the
2:18 would just be the idea that we can't
2:21 have secure knowledge of whether or not
2:23 there is actually something out there
2:25 right so we just have to if once we've
2:26 looked at all the argument we just have
2:27 to suspend judgment and we have to say
2:29 well we don't know and in the same way
2:31 in which a theological agnosticism
2:33 really know whether God exists or not I
2:34 mean there's some good arguments for the
2:35 existence of God and there's some good
2:36 arguments for atheism but nothing is
2:38 really decisive so we can just say well
2:40 I don't know now so if to suspend our
2:42 judgment yeah and then of course there
2:46 is the the the ontological atheist who's
2:50 going to present and a stronger position
2:52 who is going to say no we can actually
2:54 haven't have an argument for what the
2:55 claim that there are no such things
2:57 right there are no external objects in
2:58 the same way in which the Atheist is
3:00 going to say there's no God right we can
3:01 prove that there is no God we don't have
3:06 to suspend judgments right I in the in
3:09 this talk I set out to argue for the
3:11 stronger for this ontological atheist
3:13 position saying that we can have good
3:15 reasons to deny that they're any objects
3:16 independent of human interests and
3:19 concern right and if I understand Don
3:22 Hoffman's position correctly which I'm
3:24 not entirely sure but I think his he is
3:27 more in the former camp that says well
3:28 in the end we don't really know what
3:32 kind of things there are there and we
3:33 really have to you know we'll have to we
3:35 have to see as far as we come with
3:36 scientific methodology but then we have
3:38 we basically have to stop before
3:39 answering the final question and then
3:42 that's have to suspend judgment yeah so
3:43 that would be I mean I don't want it
3:44 attribute that view to him that that's
3:47 that's how I understand him so this is
3:48 kind of weaker position than the one I
3:50 want to want want to talk about today so
3:52 and we'll see how far we get with that
3:56 so in a sort of not sure my main reason
3:59 for this stronger ontologically atheist
4:02 claim is that such entities that such
4:04 external entities that exist independent
4:07 of human interests and concerns wouldn't
4:09 do any explanatory or theoretical work
4:11 and when we are faced with the choice of
4:13 whether or not to accept such entities
4:15 its methodologically preferable not to
4:17 do so right so if you have a theory and
4:20 then you realize that you serve one one
4:21 wheel in the mechanism doesn't actually
4:23 do anything apart from turning you think
4:24 Oh construct construct mean time
4:27 mechanism without that wheel yeah and so
4:29 that idle wheel I would argue is also
4:31 the Explorer the assumption that they
4:34 are things that exist independent of
4:36 human interests and concerns right so
4:39 that's the that's the kind of goal the
4:41 theoretical goal I'm going for but
4:44 before we get to that and of course
4:46 we'll have to see why that would indeed
4:48 be the case we have to argue that the
4:49 postulation of objects independent of
4:51 human interests and concerns is indeed
4:53 dispensable and that is a pretty big
4:58 task and I'll spend most of this talk
5:00 actually in trying to make this claim
5:06 plausible yeah ok so and I'm going to
5:10 look mainly at two arguments against the
5:17 existence of an external world and these
5:19 two arguments are the other ones that
5:21 you see here on the slide one is that
5:24 key features of our word view that seem
5:25 to necessitate the external world do not
5:27 in fact do so alright so we might think
5:28 there are certain assumptions that we
5:30 make about our everyday reality that
5:32 necessitated their external objects but
5:36 in fact that is a mistaken idea no and
5:38 the second point the be point is that
5:40 the defensible epistemology sorry
5:41 defensible epistemology is can only
5:43 postulate an external what in a very
5:45 thin sense yeah so if we think about our
5:47 best theories of knowledge our best
5:49 epistemologies then we realize that the
5:51 external world they they have to
5:54 postulate is an extremely thin and
5:56 insubstantial notion which we can't
5:59 really use in order to make it bear the
6:02 weight of the objects that exist fully
6:04 independent of human interests and
6:07 concerns so and as a conclusion of those
6:10 two we're then aiming for the claim that
6:12 therefore the assumption of an external
6:17 world is dispensable no so we'll see how
6:18 certain properties of the world that
6:20 seemed to be only explicable by assuming
6:22 the existence of mind independent
6:24 objects can in fact be explained without
6:26 them that's point a and secondly we will
6:27 see that the most promising theories of
6:29 knowledge philosophers currently defend
6:32 assume the existence of such objects but
6:34 that they do so in such a minimal sense
6:39 we can in fact get by without them okay
6:45 so let's talk about a first yeah and so
6:47 the main question is why do we think we
6:51 need to postulate the existence of an
6:53 external world and there at least two
6:55 intuitive reasons why you could think we
6:57 need that first of all to explain the
6:59 appearance of externality right so there
7:01 appears to be all that stuff around me
7:04 that is pretty independent of my
7:06 interest and concern so if I wasn't here
7:08 I think this tent probably would still
7:10 be here that's the first point and the
7:13 second point is that we use it to
7:16 explain the difference between vertical
7:21 and illusory States yeah so in
7:24 particular we are using the idea of
7:28 objects that exists independent of human
7:29 interest and concerns in order to
7:32 explain why the external world around us
7:35 seems to be coherent right so it seems
7:36 to be a non contradictory story where
7:40 everything hangs together also we want
7:42 to explain why there is such a thing as
7:45 intersubjective agreement right so I can
7:46 see this watch here and you can all see
7:48 this watch which is would be difficult
7:51 to explain if there wasn't a watch and
7:54 finally of course the notion of efficacy
7:58 right we can thinks in the external
8:00 world seem to have some sort of causal
8:02 and external causal and external
8:04 efficacy how do we explain that if these
8:10 things don't exist right okay and so
8:12 let's let's have a look at how strong
8:15 these two reasons for defending the
8:18 existence of external things really are
8:20 well I think we can deal with this point
8:22 here that we need an external world to
8:24 explain the appearance of externality we
8:26 can deal with that fairly quickly
8:29 because that it's a very strong point as
8:30 there are all kinds of epistemic
8:33 situations where we have the experience
8:34 of objects independent of human
8:36 interests and concerns while there are
8:38 in fact no such objects right dreaming
8:40 is probably the most obvious examples
8:43 hallucinations and specific kinds of
8:45 virtual reality there were contexts
8:48 where we actually have the impression
8:51 that there are things independent of our
8:54 of us our desires concerns our cognitive
8:57 states they say the the reality we
8:59 interact with in a dream but of course
9:01 there's no such things nobody assumes
9:03 that you know when you are chased by
9:04 tiger in a dream that is really some
9:06 kind of ontological entity which is the
9:07 dream Tiger such that your dream is
9:09 about that but it's just nothing it's
9:12 only the process happening in your mind
9:14 okay so I think this one is that the
9:16 second point is a lot more interesting
9:21 and that is that an important feature of
9:22 the world seems to be a distinction
9:25 between states that are political like
9:27 waking life and illusionary States like
9:29 dreams or perceptual illusions like you
9:32 know bent sticks and neurologists and
9:34 tinnitus where you hear a sound in your
9:36 ear that isn't there and so on so
9:37 recourse to mind independent objects
9:40 allows us to explain this by supporting
9:43 the claim that veridical states are
9:46 coherent in themselves and with one another
9:46 another
9:48 different people agree on them and they
9:51 produce substantial effects right so if
9:53 there were no objects of independent of
9:54 human interest and concerns the whole
9:56 veridical illusory distinction would
9:58 collapse right but this seems to be a
9:59 pretty stable distinction about how we
10:02 think about the world so the the
10:04 opponent argues such objects must exist
10:07 because if there was if there were no
10:09 external objects then we wouldn't make
10:11 sense we couldn't make sense of these
10:13 very strong intuitions we have about the
10:14 world around us
10:17 coherence into subjective agreement and
10:20 efficacy to continue watching this video
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