If we have learned nothing else from the 20th century, we should at least have grasped that the more perfect the answer, the more terrifying its consequences. Incremental improvements upon unsatisfactory circumstances are the best that we can hope for, and probably all we should seek.

The pleasures of mental agility are much overstated, inevitably - as it now appears to me - by those not exclusively dependent upon them.

There is nothing to be said for being crippled. You don't see the world better or clearer, nor do you develop some special set of skills by way of compensation.

We no longer ask of a judicial ruling or a legislative act: is it good? Is it fair? Is it just? Is it right? Will it help bring about a better society or a better world? Those used to be the political questions, even if they invited no easy answers. We must learn once again to pose them.

Although the United States lost a quarter of a million men and women, civilians and soldiers, in World War II, that's considerably less than the Russians lost in soldiers at the Battle of Stalingrad alone. It's important to convey to countries and to people and to generations who have no experience of the 20th century as it was lived in Europe just how catastrophic it was.

We have responsibilities for others, not just across space but across time. We have responsibilities to people who came before us. They left us a world of institutions, ideas or possibilities for which we, in turn, owe them something. One of the things we owe them is not to squander them.

The Second World War had a precipitating effect in that it discredited the empires, as well as bankrupting them. Not only could you no longer, if you were a colonial subject of France in Africa, look to France as a model of power and influence and civility after what had happened in the war. Nor could the French any longer afford to run their empire. And nor could the British, although they were not discredited in the way that the French were.