Is knowledge discovered, or just invented? Can we ever get outside ourselves to know how reality is in itself, independent of us? Philosophical realism raises the question whether in our knowing we connect with an independent reality--or only connect with our own mental constructs. Far from being a silly parlor game, the question impacts our lives concretely and deeply. Modern Western culture has been infected with antirealism and the doubt, skepticism, subjectivism, relativism, and atheism that attends it--not to mention distrust and arbitrary (mis)use of reality. Premier scientist-turned-philosopher Michael Polanyi stepped aside from research to offer an innovative account of knowing that takes its cue from how discovery actually happens. Polanyi defied the antirealism of the twentieth century, sounding a ringing note of hope in his repeated claim that in discovery, we know we have made contact with reality because "we have a sense of the possibility of indeterminate future manifestations." And that sense marks contact with reality, because it is the way reality is: abundant, generous, and fraught with as-yet-unnameable possibilities. This book examines that distinctive claim, contrasting it to the wider philosophical discussions regarding realism and antirealism in the recent decades. It shows why Polanyi's outlook is superior, and why that matters, not just to scientific discoverers, but to us all.