Then again, in the Muggle world, all of the extremely intelligent people Harry knew about from history had not become evil dictators or terrorists. The closest thing to that in the Muggle world was hedge-fund managers, and none of them had tried to take over so much as a third-world country, a point which put upper bounds on both their possible evil and possible goodness.
—HPMoR Chapter 86
If you had something more specific in mind, I can’t recall it offhand.
That’s the one. I misremembered and thought it was an LW post.