I could list Asimov quotes for days.

To succeed, planning alone is insufficient. One must improvise as well.

— Salvor Hardin

From the book Foundation.

Also from Foundation:

Never let your sense of morals prevent you from doing what is right.

— Salvor Hardin

Which I particularly love, because it begs the question: “Are morals universal or relative?”.

Interesting side-story – “Are morals universal or relative?” was one of the original 29 Saberr test questions! I always used to answer ‘universal’, but now I might have to answer differently…