As far as anyone is aware, the universe consistently acts according to predictable laws (and scientific inquiry exists to determine those laws). Is there any metaphysical reason for this? Is such a question even answerable?
EDIT: I think my question was misunderstood, so I'll try to clarify. I know about the mathematics question, but this question is, why is the universe consistent? It's related to the problem of induction: just because all hitherto observed emeralds are green doesn't necessarily mean that all emeralds are green. Yet, those who have hypothesized that emeralds are green have (thus far) been found to be correct. In other words, as far as anyone can tell, the universe is consistent to the point where much of its behavior is predictable using known laws and statistics. Is there any philosophical discussion regarding why that appears to be the case?
FURTHER EDIT: The question is more fundamental than the simple, 'why are all emeralds green', to which the answer is obviously, 'because if it wasn't green, we wouldn't call it an emerald', and once I formulate the question better, I think that the answer becomes obvious. Let's use an actual law, F=ma. We've checked rocks, we've checked feathers; we've checked slow moving objects and fast moving objects, and yet, lo and behold, the law always seems to be true, and it's stayed true for at least a few hundred years (but we can reasonably assume that it was just as true a millennium ago). Now, I ask the metaphysical (in the most literal sense) question: why is this law always true? Why does the universe behave so consistently?
If I may edit in what I believe is the answer to this question (and let a moderator delete this paragraph if it's inappropriate): the answer is that Newton's second law of motion is used to describe what we observe, but if we'd observe inconsistencies, we'd use different laws for different situations. In our example, what happens when the object is moving so quickly that it approaches the speed of light? Then Newton's law isn't perfect; we need special relativity. The question of the universe's consistency is therefore quantitative, a question of degree: why is the universe as consistent as it is? Why does one law of motion hold so often, and that the mass-force relationship is effected by other variables so rarely? The proper response, I think, is the anthropic principle: a less ordered universe wouldn't sustain life.