Leonard Bernstein said this quote

The gift of imagination is by no means an exclusive property of the artist; it is a gift we all share; to some degree or other all of us are endowed with the powers of fantasy, the dullest of dullards among us has the gift of dreams at night - visions and yearnings and hopes. Everyone can also think; it is the quality thought that makes the difference - not just the quality of logical thinking, but of imaginative thinking. And our greatest thinkers, those who have radically changed our world, have always arrived at their truths by dreaming them; they are first fantasized, and only then subjected to proof.