Possibility
I conceive of philosophy as the inquiry into unexamined assumptions. This could be done for its own sake, but philosophy also serves the useful function of generating hypotheses, specifically, that the assumption is false. In this way new possibilities are revealed. For example, one day it occurred to someone gazing at the sky that she had been assuming that the motion of the stars and planets (including the Sun and Moon) in the sky meant that they were all revolving around the Earth. This immediately suggested the hypothesis that they weren’t, but instead (or in addition) the Earth was rotating. Of course it won’t always turn out that one’s assumption was false; but the value of philosophy, or of this philosophical attitude, is that it raises a question that had never been asked before, which sometimes leads to a surprising and even Earth-shaking (or literally Earth-moving, as in rotating) discovery. Often we rely on science to carry the ball at that point to determine the answer,