You could argue that Occam's Razor is a reasonable distribution on prior probabilities. But what is a "reasonable" distribution?

If you make the assumption that what you observe is the result of a computational process, the prior probability of a lossless description/explanation/theory of length l becomes inversely proportional to the size of the space of halting programs of length l. You're free to dismiss the assumption, of course.

"But," you cry, "why is the universe itself orderly?"

If you make the assumption that what you observe is the result of a computational process, the prior probability of a lossless description/explanation/theory of length l becomes inversely proportional to the size of the space of halting programs of length l. You're free to dismiss the assumption, of course.

One reason among many may be the KAM-Theorem.