In modern pharmacology it's so clear that even if you have a fixed dose of a drug, the individuals respond very differently to one and the same dose.
“The goal of life is to make your heartbeat match the beat of the universe, to match your nature with Nature.”
“I think I was always subconsciously driven by an attempt to restate that faith and to show where it was properly grounded, how it grew out of what a great many young men on both sides felt and believed and were brave enough to do.”