Roger Martin is one of my favourite business writers.
This short piece on strategic thinking and how it differs from being smart is a gem:
“The problem with smart people is that they are used to seeking and finding the right answer; unfortunately, in strategy there is no single right answer to find. Strategy requires making choices about an uncertain future. It is not possible, no matter how much of the ocean you boil, to discover the one right answer. There isn’t one. In fact, even after the fact, there is no way to determine that one’s strategy choice was “right,” because there is no way to judge the relative quality of any path against all the paths not actually chosen. There are no double-blind experiments in strategy.”
Martin notes that the essential qualities for this type of person are flexibility, imagination, and resilience.