[QUOTE=Half Man Half Wit]
I’m not sure about that; I think there are examples of paraconsistent logics (i.e. logics that allow true contradictions) that lack transitivity, so this seems to assume an universe governed by classical logic (or at least some logic where transitivity holds), which I don’t think is necessary. Even our own universe is not wholly subject to classical logic – the quantum world lacks the principle of distributivity, for example; a and (b or c) = (a and b) or (a and c) can easily be shown to be false via example:
a: The particle is moving to the right
b: The particle is to the right of the origin
c: The particle is to the left of the origin
Thus, (a and (b or c)) is obviously true, but both (a and b) and (a and c) are false, since uncertainty doesn’t permit an exact determination of the particle’s position and momentum, and hence, ((a and b) or (a and c)) is false, too.
But I’m really no expert on the subject, so I’d appreciate any corrections to my reasoning.
[/QUOTE]
Well, the transitivity of > isn’t a purely logical question in most contexts, but, rather, just part of the definition of a partial order (a reflexive, transitive relation). But, I suppose, the most logic-oriented analogue would be the principle that (A implies B) and (B implies C) should entail (A implies C). I guess this could fail in some reasonably standard systems of paraconsistent logic [e.g., by taking A to be true, C to be false, and B to be one of the other values in Belnap’s four-valued logic].
As for quantum logic and failure of distributivity, I wouldn’t so much say that the quantum world lacks the principle of distributivity; rather, I would say, that when formal propositions are interpreted in a certain useful way as statements about quantum mechanics, then distributivity is not validated; however, other ways of bridging from formal propositions to actual claims about quantum mechanics will validate distributivity.
You could never hope to show that “the real world’s logic” is one thing rather than another, any more than you could hope to show whether real space used Cartesian coordinates or spherical coordinates; a logic is just a particular language and framework within which to describe and analyze things. Any such framework is potentially applicable, via some interpretation or another, to any system under study; the only question is whether it applies naturally and usefully. [As a very rough analogue, let’s consider the following argument that logic of “the real world” is intuitionistically-flavored: classically, we can show that for every x in [0, 1], there exists a y in [0, 1] which is distinct from it (e.g., if x is 0, let y be 1; if x is not 0, let y be 0). But one might believe that every function in the real world is continuous, and it’s easy to see that there is no continuous function y(x) from the unit interval to itself with the property that y(x) is always distinct from x. Is this a problem for the classical logician? No, it’s only a problem if one wanted to interpret statements like “for all x, there exists a y” in a certain way as assertions about the real world. It is, of course, very easy to interpret them in another (more standard) way which is compatible with classical logic, though for some purposes the one interpretation may lend itself to greater usefulness in analyzing the real world than the other. It’s the same sort of thing that happens with so-called “quantum logic”. There are various formal frameworks out there which can be used to analyze quantum mechanics, bringing out this or that aspect of it; some of these frameworks are classically oriented and some are not, but it’s not as though there’s a substantive question of which one is “correct”].
This is all a bit off-topic, and sort of “fuzzy”, for lack of a better word, but, then, this is a sort of insubstantial “fuzzy” thread to begin with, so I don’t feel particularly guilty.