> You're not getting gold, you're restoring fairness where the rule or law is unfair.

But how do you know what's fair? More to the point, how do you know what all the other people, whom you're supposed to treat the way they themselves would like to be treated, think is fair? You've assumed that cheating on an exam which you believe to be unrelated to the course material is "fair"; how do you know all the other people who are affected by your action would agree?

Also, I probably should have made it clearer at the outset that judging that something is "unfair" to you is highly subjective and prone to error. I do not really believe that the exams the Harvard students cheated on were "unfair"; I think the students were just too lazy to learn the material and then tried to weasel out of the consequences. But they themselves probably sincerely believe that the exam was unfair and unrelated to the course. The fact that so much was at stake makes their judgment that the exam was unfair quite different from, for example, my judgment that I know better than the people who put up speed limit signs what a "safe" speed is under the current driving conditions. See further comments below.

> You get the gold by leveraging your renewed equal opportunity.

Cheating doesn't give you "equal" opportunity; it gives you an extra opportunity that the people who don't cheat don't have. Whether that is actually "fair" is, as I said above, highly subjective, and it's very easy to judge wrongly if you have a strong personal stake in the outcome. That's why we have ethical norms that don't allow people to make such judgments unilaterally in cases where self-serving judgments are highly likely and have large consequences.

Since I asked for a principle that distinguishes when it's OK to "cheat" and when it isn't, I should offer one of my own--actually two, following on from the above comments. I see at least two key differences between, for example, the case of exceeding speed limits, and the case of cheating on exams:

(1) I can make a good case that I, driving my car on a particular road under particular conditions, can better judge what a safe speed is in that situation than lawmakers or regulators who just have very general rules for setting speed limits: I am there and they are not, and I'm the one who risks injury if I have an accident. So I have more information and am motivated to make good judgments. The case of students cheating on exams is opposite in these respects: the students do not have more information than the professor does, and they are highly motivated to make self-serving judgments about whether the exam is "fair", rather than accurate ones.

(2) I gain no significant advantage over other drivers from speeding. I get where I'm going faster than I otherwise would, but that does not hinder any other driver from getting where they're going. There's no competitive element involved. In the case of students cheating on exams, there certainly is a competitive element; a student who cheats does not just gain an advantage, he takes away an advantage from others.

So I would distinguish "cheating" that should be prohibited from infractions like speeding, by these two principles: the motivation for self-serving judgments, and the competitive element where one person gaining an advantage means others lose it.

> The Golden Rule doesn't only demand that you treat others that way; it also demands that others treat you that way, which may require action on your part.

I'm not sure the Golden Rule includes this, but that's an argument about terminology, not ethics. Basically, you're saying that you have to let other people know how you want to be treated. I agree with that general principle, but I'm not sure cheating accomplishes that purpose. Are the students who cheated at Harvard being treated more like they wanted to be treated because they cheated?