On Tue, May 11, 2010 at 10:29 PM, Brent Meeker <meeke...@dslextreme.com> wrote: > > I'm confused about your theory of this, Rex. You talk about "honest" vs > "dishonest:" universes and how the initial conditions must determine what > theories we have about the universe
This point about initial conditions and causal laws "determining" what follows, including our discovery of various theories, is reasonable isn't it? IF you assume a physicalist view of reality, of course. > and since there are a lot more dishonest > ones than honest (a point not in evidence) we have no reason to believe our > theories of the universe. So the "no miracles" part of my title is a reference to Hilary Putnam's observation: “The positive argument for realism is that it is the only philosophy that doesn't make the success of science a miracle” This is discussed here: http://plato.stanford.edu/entries/structural-realism/ As to my statement that "It seems to me that this set of deceptive universes is likely much larger than the set of honest universes", my reasoning is: 1) If we assume physicalism/materialism 2) and if we assume that a computer simulation of a brain+environment would give rise to the same conscious experience as a real brain in a real environment (i.e. multiple realizability) 3) Next, we know that there are infinitely many different Turing machines capable of running any given computer simulation. 4) We can therefore conceive of a universe containing nothing but an implementation of such a Turing machine. 5) And we can therefore conceive of infinitely many universes, each containing a different Turing machine that runs the same "brain simulation" program. 6) Therefore it's conceivable that there could be infinitely many of these deceptive universes running "Matrix"-style simulations of *any* "honest" universe. So how many honest universes can there be that will "honestly" generate our conscious experiences? I would think that the more accurate our observations become, the fewer universes there are that can honestly generate them... With maximumly accurate observations, then only 1 universe (and it's exact duplicates) could honestly generate those observations. Though maybe we get into quantum uncertainty issues here. > But then you cite Schulze and Kant who contend > that you have no reason to think there is a universe or causal laws or > anything except your cognitions. Well, Kant contended that we had good reason to believe that a noumenal world existed...but that we couldn't know anything about it beyond the fact of it's existence. He explicitly addressed this in the "Refutation of Idealism" which he added to the second edition of A Critique of Pure Reason (1787) to avoid the charge that his Transcendental Idealism was just a variation of Berkeleyan Idealism. Schulze basically showed that Kant's arguments against Cartesian Doubt, Berkeleyan Idealism, and Humean Skepticism didn't go through. According to Schulze, Kant's arguments end up strengthening the case for these views, instead of countering them. Interestingly, one of the reviewers of Schulze's Aenesidemus was Johann Fichte (1764-1814), who came to this conclusion: "Fichte did not endorse Kant's argument for the existence of noumena, of 'things in themselves', the supra-sensible reality beyond the categories of human reason. Fichte saw the rigorous and systematic separation of 'things in themselves' (noumena) and things 'as they appear to us' (phenomena) as an invitation to skepticism. Rather than invite such skepticism, Fichte made the radical suggestion that we should throw out the notion of a noumenal world and instead accept the fact that consciousness does not have a grounding in a so-called 'real world'. In fact, Fichte achieved fame for originating the argument that consciousness is not grounded in anything outside of itself." So. There's nothing new under the sun... > You can't draw any conclusions about > probability from that. Before you can count up the infinite number of > "Matrix" universes and Boltzmann brains, you need to suppose there is > something beyond your own thoughts. So I guess in the future I need to be more clear about where I'm assuming physicalism to make arguments against it. I'm not actually arguing that "Matrix" universes and Boltzmann brains exist. I'm saying that IF we assume Physicalism, I don't see how we can rule out Matrix universes and Boltzmann brains, except by fiat. They seem to be "likely" consequences of Physicalist assumptions. As likely as the mainstream physicalist conclusions that the world really is (generally) as it appears to be. I commented on Sean Carroll's position on "Cognative Instability" in "The Past Hypothesis" thread. Cognative instability is only a problem if you refuse to relinquish the starting assumption that an independently existing physical world is the cause of our experiences. > And I doubt you've had an infinite > number of thoughts about anything. If physicalism and eternal recurrence are true, then I've had the same few thoughts an infinite number of times! Does that count? Tangentially: isn't your claim that you are only interested in theory to the extent that it is "useful", essentially a skeptical position? -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-l...@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
