Good argument; but it’s not certain to be correct.

The same argument could be made about (for example) elliptical orbits versus epicycles (geocentric orbits): the only solid physical evidence for non-geocentricity is that we observe that all orbits are elliptical, and that the law of gravity neatly explains that (modulo relativity, gimme a break here . This is actually physically accurate, by the way; there is no physical reason NOT to call the Earth the center of the universe; the only reason is that doing so makes us have to solve equations with epicycles in them instead of simple ellipses.

So the question THERE truly is what system makes reasoning simpler. It’s quite plausible that this is also the question here as well.

-Wm

Psymon: Isn’t that a bad argument, though. “This must be true otherwise it makes my life difficult” is a pretty crappy argument. If you really want the law of non-contradiction, argue it on its own strengths, not on the question of convenience for philosophers: I have a hunch that nature doesn’t actually care whether or not it’s being convenient for philosophers.

Most paradoxes, in my experience, are a result of the described setup being impossible. As for time travel paradoxes, I subscribe to the “red queen’s race” model–if time travel is possible, the time travel to the past is already incorporated into the present, so any attempted changes in the past only serve to bring about the present. Time travel is probably so confusing because we have no experience with it (like how we try to use Newtonian physics in situations where Einstein’s relativity is much more accurate–which leads to trouble when you try to use Newtonian laws to change frames of reference at relativistic speeds)