Earlier quoted context omitted.
Well the no free lunch theory is I think wrong, we are vastly better off with modern medicines. We are already getting free lunches of longer and heather lives. My experience, obviously not scientific, with modafinil is mild mania, grumpiness/quick to anger (What I think is the tiredness coming through), increase concentration and attentiveness to a task. My intelligence goes down. Mixed with alcohol it can cause bla…
You're missing his point, which is a reasonable one. If the human body truly functioned better with modafinil, then evolution would have given us humans that naturally produced modafinil. That isn't the case, so the assumption is there is some downside to the drug, and one that actually outweighs the positives. However, the article makes modafinil seems like an obviously positive thing and that taking the pill fixes…
Humans have already stepped outside the boundaries of natural evolution. We make casts and hardware for broken limbs; form societies and specialized communities; use drugs to resolve medical issues in individuals that evolution would've killed off. Although as a species we probably rose to dominance by being long-distance runners, most of us can't run a marathon today, because we no longer need to.
Likewise, evolution didn't make humans naturally better at living in cubicles focusing on a tiny device for many hours a day over the course of the last 50 years. The natural wiring for human neurology is still geared towards being aware of our environment, distracted by sounds and sights and things going on, because that's how you survive sneak attacks from predators or spot camouflaged prey.
It's smart to be skeptical of anything claiming to be a miracle cure, but not on the basis of some kind of spooky evolutionary action. Rather, we haven't yet gotten a great track record of coming up with chemicals that can do only one thing to our brains without upsetting some other aspect of our neurochemistry, and that's largely because the brain is wickedly complex and only recently are we starting to make some progress in understanding how it works. I have no doubt that one day we'll be able to fine-tune our own neurochemistry with few side-effects, but today might not be that day.