As found in the otherwise maddeningly frustrating first few pages of Barry N Malzberg’s BREAKFAST IN THE RUINS:

“Science fiction is a way of thinking about things.”

– Frederik Pohl

Which may seem like a small notion. But it’s possibly the best working definition of sf I’ve yet come across, insofar as it does the crucial business of inviting the body in front of you to consider sf as a tool with which to understand the contemporary world.