Patriotism once united us. Now it divides us.

Lincoln had discovered for us the truest touchstone of republican patriotism: the unifying power of our common national memory. Memory is both conceptual and visceral. It lets us take pride in our ideals and our experience — our origins and our progress — and the fact that both are ours. It can serve as a fountain of affection because it is shared with our fellow citizens, not simply as a set of principles but as a life lived together.

A patriotism of common national memory could be the answer to the riddle of a politics divided over how to be unified. It is not a way to make our differences go away, but rather to allow us better to live with them and so with each other. It could help counteract our tendency to think of our political opponents as speaking from outside the American tradition, and so as threats to be warded off rather than fellow citizens to be engaged. Our tradition is more capacious than we tend to imagine and gives us more room for genuine politics than we too often assume.

A love of country rooted in national memory would let us draw some good out of the ways in which we are now divided over patriotism.