The trope is Villains Act Heroes React, and the Foundation stories don't actually defy this AFAIC recall.
It does in various points of the saga, some examples I can give easily, other are spoilers so I'll ROT13 them.
In the first tome and the prequels, it's Harry Seldon who tries to develop pyschohistory and setup the Foundation, and different "villains" react to that. It's true that afterwards the Foundation is mostly reacting to Seldon Crisis, but those crisis are part of Seldon's Plan (so, of the hero planning ahead awesome things).
In the last tome, Foundation and Earth, it's clearly the heroes who start their own quest of finding back the Earth.
N...
Another month, another rationality quotes thread. The rules are: