Why should we prefer simple and elegant theories, the empirical evidence being equal? There are two standard answers (besides the answer that no, we shouldn't):
- truth: beautifully simple theories are more likely, all other things being equal, to be true
- pragmatic: simple theories are easier to work with.
- aesthetic: just as it's better to hang around beautiful places, it's better to hang around beautiful theories.
But I think there is a bit of truth to the aesthetic suggestion. When you have multiple equivalent formulations of the same theory, why not spend more time with the more beautiful ones, simply because they are more beautiful? Of course, this could be defeated by more pedestrian pragmatic concerns, because a more beautiful formulation can be harder to actually work with. (Actually, that last point suggests that (2) can't be the whole story about preference for elegant theories.)