PhilosophyFTW

This post demonstrates a deep misunderstanding of modal logics, and of the notions of possibility and necessity. one would expect that misunderstanding given that Eli can't really get himself to read philosophy. For example:

"I have to make an AI out of electrons, in this one actual world. I can't make the AI out of possibility-stuff, because I can't order a possible transistor."

What? What kind of nonsense is this? No contemporary philosophers would ever say that you can make something out of "possibility stuff", whatever the hell that is is supposed to be.

Or this:

"It's going to be because the non-ontologically-fundamental construct of "possibility" turns out to play a... (read more)

I'm hardly claiming that if we find some true future unified theory of physics, every physical proposition we current believe is false. To assert that would be absurd. The interesting question is which of the propositions that are part of the current packages (at least one of which is false) are in fact false.

If you want to pick some of those propositions and rely upon them, you'd better have independent evidence for their truth (the accurate predictions made by the package isn't going to count). So rely on that as your evidence, and not on the false package. This is what less wrong people would do.

Barbour is engage... (read more)

What you put in for P and Q is irrelevant, for a simple reason. If you're appealing to Q as your only evidence for P, and Q is probably false, then you don't have good evidence for for P. If Eliezer wants to appeal to some Q as his only evidence for P, and Q is probably false, then he has failed.

Of course, if you have independent evidence for P, then you don't need to appeal to P as your evidence for Q (and you shouldn't, since P is very probably false). Here you can appeal to the independent evidence. For example, there is evidence that the earth... (read more)

As I have pointed out, the theory to which he is appealing is very probably false. If he wants to appeal to it in defense of his claims (and even then there are several other reasons why his claims almost certainly don't follow from the theory), he needs to do so with much more humility. You don't get to infer P from Q which is probably false, and then assert P with conviction. This is irrational and more wrong (if you know that Q is probably false, which he should), not less wrong. My inference is "The physical theories to which he is appealing are very probably false.... (read more)

Eliezer might well benefit by thinking about the above-linked SEP article in which this claim is broached: "We now appear to have an interesting situation. Quantum mechanics is compatible with two distinct metaphysical ‘packages’, one in which the particles are regarded as individuals and one in which they are not. Thus, we have a form of ‘underdetermination’ of the metaphysics by the physics (see van Fraassen 1985 and 1991; French 1989a; Huggett 1997). This has implications for the broader issue of realism within the philosophy of science. If asked to spell out her beliefs, the realist will point to currently accepted fundamental physics, such as quantum mechanics, and insist that the... (read more)

In the simplest of terms, theory T is inconsistent with theory T if the conjunction of T and T entails everything in a classical logical system.

Since QM is inconsistent with GR, and since not every proposition is true, either QM or GR is, strictly speaking, false. Perhaps both are false.

The OP, Eliezer, must think that GR is false, since he's gone out and endorsed QM. This is not a good position to be in. More charitably, the OP has tried to endorse everything in QM that he thinks he needs for his argument, and he's asserted that all that requisite material will be retained in any future scientific theory.... (read 391 more words →)

Relying upon Wikipedia is not advised here. QM and GR, if you stick them together, entail everything. (On the assumption that from a contradiction one can derive anything. Paraconsistent logical systems deny this assumption.) For some proposition, sentence, statement or utterance that P, QM entails P. GR entails not-P. Absent abandoning classical logic (and moving to something like paraconsistent logic), GR and QM are inconsistent.

Let's assume that a theory is false if the theory entails P and not-P (that is, let's ignore paraconsistent logical sytstems). Then sticking GR and QM together entails P and not-P. Any theory that entails both P and not-P is false.... (read more)