From Kevin Williamson, History is Short in National Review:

There is no marriage as stable and enduring as that of ignorance and certitude.

Years ago, I knew some crunchy progressives of the particularly nasty kind they cultivate in the few remaining blueblood enclaves of the old WASP Main Line. There is something about the combination of genuine privilege, Quaker moralism, and macrobiotic diet that makes these particular partisans of peace and tolerance the most vicious and intolerant of their kind but far from the brightest, as in the case of the woman who sniffed that she could hardly endure trips to visit her husband’s family in the South because she was physically nauseated just by being present in a place that had once seen slavery. She said this with practically orgasmic moral self-satisfaction while standing on what had been the grounds of Richard Harrison’s tobacco plantation, the largest slave operation of its kind in pre-Revolutionary Pennsylvania. She had a keen sense of morality but a somewhat less keen sense of history.

And that can be a dangerous thing.

I do not believe that only those who fail to study history are doomed to repeat it. Plenty of people who study history are entirely capable of making the same mistakes as their ancestors, and worse ones, too. Practical application is not the first, best, or only reason to study history and try to learn something from it — which is not exactly the same as learning something about it — but give that fair consideration, too. Thanksgiving may put us in a historical mood, and different people tell different stories about the founding of this country and what came next. They do not always have the best or most honest reasons for preferring one version of that story to another. But each of us, possessed of the knowledge of his own nearly boundless ignorance (how many things do you really know about?), ought to have a little modesty and a little humility, enough to hope that we might see a little light in some of those other versions of the story, and that we might expand the circle of light outward a little, pushing back the darkness as best we can.