I don't think you've given enough information to make a reasonable choice. If the results of all 20 experiments are consistent with both theories but the second theory would not have been made without the data from the second set of experiments, then it stands to reason that the second theory makes more precise predictions.

If the theories are equally complex and the second makes more precise predictions, then it appears to be a better theory. If the second theory contains a bunch of ad hoc parameters to improve the fit, then it's likely a worse theory.

But of course the original question does not say that the second theory makes more precise predictions, nor that it would not have been made without the second set of experiments.

And are you really "exploiting" an "irrational" opponent, if the party "exploited" ends up better off? Wouldn't you end up wishing you were stupider, so you could be exploited - wishing to be unilaterally stupider, regardless of the other party's intelligence? Hence the phrase "regret of rationality"...

Eliezar, you are putting words in your opponents' mouths, then criticizing their terminology.

"Rationality" is I think a well-defined term in game theory, it doesn't mean the same thing as "smart". It is trivial to construct scenarios in which being known to be "rational" in the game theory sense is harmful, but in all such cases it is being known to be rational which is harmful, not rationality itself.

Personally, I pretty much always have checked baggage, I can always make it to baggage claim before my luggage does, so I don't really care about saving time getting off the plane. If I'm in a window seat I usually let people behind me get off first, but if I'm in an aisle seat I don't want to block in the person in the window seat.

Which moral system the human race uses is relative, arbitrary, and meaningless, just as there's no reason for the pebble sorters to like prime numbers instead of composite numbers, perfect numbers, or even numbers

But that's clearly not true, except in the sense that it's "arbitrary" to prefer life over death. It's a pretty safe generalization that actions which are considered to be immoral are those which are considered to be likely to cause harm to others.

But which others matter how much is an open question. Some would suggest that all humans matter equally and that only humans matter, but I don't buy it, and I don't think many others do either. For example, I (and I think everyone I know) would agree that we should make at least some effort to avoid causing suffering to animals, but that it would be going way to far to treat a rat or a pig as equally important as a human. I understand that there are people out there who think it's perfectly appropriate to treat a pig as nothing but a machine for turning corn into meat, and others who think we out to consider a pig every bit the moral equal of a human being, and I acknowledge that either position is better defined and more internally consistent than my own. I can't see anything "wrong" with either extreme position, I see no reason to believe anyone could convince the others of the "rightness" of his position, even in principle.

It's strange that these pebblesorters can be convinced by "a heap of 103 pebbles and a heap of 19 pebbles side-by-side" that 1957 is incorrect, yet don't understand that this is because 19 * 103 = 157. Admittedly I didn't notice this myself on first reading, but I wasn't looking for a pattern.

I don't think your analogy holds up. Your pebblesorters all agree that prime numbered piles are correct and composite ones incorrect, yet are unreflective enough not to realize that's how they are making the distinction and bad enough mathematicians that they can't reliably tell whether or not large numbers are prime. If only they were smarter, all their disagreements would go away. The question of why prime piles are correct, or why piles should be made at all, would be forever unanswerable, but it wouldn't matter much.

I think with human beings the moral disagreements are fundamental. There is no equivalent of a universal belief that primality = goodness. It's not just that we make calculational errors (although of course we do). It's not just that we aren't consciously aware of the fundamental criteria by which we as individuals evaluate things as morally "good" or "bad" (although of course we aren't). Something like a universal agreement as to what these fundamental criteria are just isn't there. Not consciously, not unconsciously, not waiting to emerge, just not.

At least, I don't think it is.

I think everything you say in this post is correct. But there's nothing like a universal agreement as to what is "good", and although our ideas as to what is good will change over time, I see no reason to believe that they will converge.

There's a big difference between saying "morality is the product of human minds" and saying "morality is purely arbitrary". Similarly, there's a big difference between saying "there are objective reasons why we make the moral judgments we do" and "all moral questions have objective answers which in no way depend on human minds".

Life is not a zero sum game. I think nearly everyone would agree that it would be advantageous to nearly everyone if one could somehow guarantee that neither one's self nor one's loved ones would be killed at the cost of forgoing the ability to kill one's enemies. I think this fact, not repeated arbitrary assertion, is the basis for the nearly universal belief that "murder is wrong". I think the fact that, in many societies, refraining from killing those outside one's own tribe does nothing to prevent those outside the tribe from killing one's self or one's loved ones, and not arbitrary bigotry, is the reason that in those societies killing those outside one's tribe does not count as murder.

I think it's probably useful to taboo the word "should" for this discussion. I think when people say you "should" do X rather than Y it means something like "experience indicates X is more likely to lead to a good outcome than Y". People tend to have rule-based rather than consequence based moral systems because the full consequences of one's actions are unforeseeable. A rule like "one shouldn't lie" comes about because experience has shown that lying often has negative consequences for the speaker and listener and possibly others as well, although the particular consequences of a particular lie may be unforeseeable.

I don't see how there can be agreement as to moral principles unless there is first a reasonably good agreement as to what constitutes good and bad final states.

Slightly OT for this thread: there should always be a prominent link on the right to the open thread. As things are, it gets heavy usage the first couple days of the month, then falls off the bottom of the page before anyone can read most of the comments. Look, it's gone again already!

I know I've said this before, but I think it was on the open thread and it fell off the bottom of the page before anyone read it.

Why do people seem to mean different things by "I want the pie" and "It is right that I should get the pie"?

These really are different statements. "I am entitled to fraction x of the pie" means more or less the same as "a fair judge would assign me fraction x of the pie".

But a fair judge just means the judge has no personal relationship with any of the disputing parties and makes his decision based on some rational process, not arbitrarily. It isn't necessarily true that there's a unique solution that a fair judge would decide upon. One could say that whoever saw it first or touched it first is entitled to the whole pie, or that it should be divided strictly equally, or that it be divided on a need-based or merit-based, or he could even make the gods must be crazy/idiocy of Solomon solution and say it's better that the pie be destroyed than allowed to exist as a source of dissent. In my (admittedly spotty) knowledge of anthropology, in most traditional pie-gathering societies, if three members of a tribe found a particularly large and choice pie they would be expected to share it with the rest of the tribe, but they would have a great deal of discretion as to how the pie was divided, they'd keep most of it for themselves and their allies.

This is not to say that morality is nothing but arbitrary social convention. Some sets of rules will lead to outcomes that nearly everyone would agree are better than others. But there's no particular reason to believe that there could be rules that everyone will agree on, particularly not if they have to agree on those rules after the fact.