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.

History can show you that it was one pile of bad stuff after another. It can also show you that there's been tremendous progress in knowledge, behaviour, laws, civilisation. It cannot show you that there was a meaning behind it.

The East European small countries have a sense of betrayal, of having been forgotten by Western leaders.

Contrast 1968, when the CEO of General Motors took home, in pay and benefits, about sixty-six times the amount paid to a typical GM worker. Today the CEO of Wal-Mart earns nine hundred times the wages of his average employee. Indeed, the wealth of the Wal-Mart founder's family in 2005 was estimated at about the same ($90 billion) as that of the bottom 40% of the US population: 120 million people.

The different American experience of the 20th Century is crucial because the lesson of the century for Europe, which essentially is that the human condition is tragic, led it to have a build a welfare system and a set of laws and social arrangements that are more prophylactic than idealistic. It's not about building perfect futures; it's about preventing terrible pasts. I think that is something that Europeans in the second half of the 20th century knew in their bones and Americans never did, and it's one of the big differences between the two Western cultures.

Judaism for me is a sensibility of collective self-questioning and uncomfortable truth-telling. I feel a debt of responsibility to this past. It is why I am Jewish.

As citizens of a free society, we have a duty to look critically at our world. But if we think we know what is wrong, we must act upon that knowledge.