Getting "high" is generic slang for the consumption of some mind altering substances for fun.

The point is that you're arbitrarily defining which substances and what uses qualify as fun. If you snort a line of coke and then write a paper is that getting high or not? If you take Ritalin and play Xbox is that getting high or not? If you smoke marijuana because you feel it allows you to have better ideas is that getting high or not?

There is no heuristic here, no fact-based rule for whether we acknowledge the different states of consciousness or not. We've just taken the exact same activity that people have been doing with stimulants for decades and given it a more palatable marketing label.

This is not at all comparable to those taking the pill in the prescribed fashion in the same dose that one would take for ADD.

The drug has the same effect either way, with only slight differences between methods of delivery. The drug does not care why you take it. In any event, we are specifically not talking about anyone taking it for the treatment of an actual deficiency of functioning (controversy over ADHD aside), we're talking about people taking it for "cognitive enhancement", where the indicated dosage is none.

...they'd be used by the vast majority of athletes just like every other legal substance they've found that works.

There are plenty of legal substances frequently banned in competitive sports. For example: Ritalin, Adderal, and modafinil.

I fail to see how it affects you.

Exactly. Can you understand why that would bother me? I'm talking about broad sweeping changes in cultural norms that could potentially redefine what we expect from individuals in society to standards set by people on drugs that make them perform certain tasks at superhuman levels -- in essence doing to our civilization what we've done to professional baseball -- and all you're doing is arguing with my use of the term "getting high" to include "tweaking".

Social norms effect everyone that desires to participate in society. I want those norms to be reasonable because I happen to want to participate in society, and what I see happening with these drugs seems unreasonable, expecially when seen as a long-term trend.

In ten years, am I going to have to take drugs in order to hold a decent job? In twenty years, is my child going to have to take drugs in order to get into college? More generally: what will be the long-term large-scale effect of using drugs that alter the mesolimbic reward pathway? What reason do I have to not be concerned about these possibilities?

If someone wants to take a pill - widely considered safe - to make themselves perform better, who's business is that but theirs?

If everyone were free to take whatever drug they want for whatever purpose they want, that would be a good point. But that isn't the situation we have. A person can only take some drugs for some purposes if obtained in some ways. It is already everybody's business and we already have strict laws and rules specifying which pills you have to take, what kind of performance is acceptable, and who gets to decide if you can take them.

I don't want more constraints on what people are allowed to do with themselves than already exist, and in general my preference would be for less, but I do want less of this irrational exuberance that treats normal baseline human cognition as a disease to be medicated.