You cannot, and I resent your attempt to do so. You're just retreating into vagueness instead of arguing pertinent points. You're also projecting opinions on me that I haven't stated, apparently because you're more comfortable with parrotable dogma than relating your own opinions. Suddenly, instead of arguing for my own specific statements, you expect me to argue against extremely general statements about technology and phrophetic claims of inevitibility. You'd might as well say "God wills it" for all the passivity and coarseness of thought you've expressed here.
You're making the worst sort of argument that a person can make about transhumanism when you pretend that everything with turn out perfectly in some distant future regardless of the actions taken by people in the meantime. That is faith, not reason, and I'll have no part of it.
Reality is not an implementation detail. We're done here.
> but I do want less of this irrational exuberance that treats normal baseline human cognition as a disease to be medicated.
Ah, but it is. Some of us feel extremely limited by biology and regardless of what others feel is or isn't normal, we're going to push biology beyond what nature provided because we can. This doesn't just apply to drugs, in the next 100 years as biotechnology really takes off, people are going to be augmenting everything they can. Transhumanism is coming whether you like it or not.
If I can implant artificial memory to surpass the abilities of the brain nature provided me, I will, and so will many others, and no amount of clinging to the past or to what nature intended will prevent this from happening.
What you fear, is inevitable, the march of technology will not be stopped because people who don't want to augment cry foul when augmented people are out competing them, that's just how it's going to be.