A new point I really haven't brought up...
Say we have your situation, except that one person has three hours to study, and one has ten. Let's pretend that the hours that are available are not due to laziness or some other controllable concept. For instance, the student with less hours has to work, and the student with more hours has his rent and food paid for by daddy.
Now, since we have two people with equal intelligence, but one is unfortunately deprived of the same study time due to uncontrollable variables, we can still consider that fair?
In this case, wouldn't it be more fair if the student without as much study time took a Ritalin and therefore was able to get an equal amount of studying done as the other student who gets off easy due to having a rich family? I mean, technically, having a rich family is pretty similar to popping a Ritalin. Not everyone has access to it. But in this case, it isn't a discussion of morality, but a REAL case of true disadvantage.
That's why this, "It's not fair!" argument is so silly. Life isn't fair. It's never going to be fair. So if you have a student who wants to pop a Ritalin, it's not that this student has an "unfair advantage" over the world. That student may have an advantage over the students who work, party, AND don't take Ritalin, but the pill itself isn't going to give the student an advantage over some guy who can sit at home all day, does 12 hours of college a semester, and have daddy take care of all the finances in the background.
Illegal or not, cheating has to be measured against a standard. And if the standard is the average college student, well, I can say that the methylphenidate isn't particularly high on the list of things we should be looking for ways to balance out...