“We are a people of the frontier, born to it, bred to it, looking always toward it. And when the frontiers of our own land are gone, when we have drawn them all into an ordered world, then we must seek other frontiers, the frontiers of the mind beyond which men have not gone, the frontiers that lie out beyond the stars, the frontiers that lie within our own selves, that hold us back from what we would do, what we would achieve.”
