Two explorers set out on a journey from which only one of them will return. Their unknown land is that often fearsome continent we call the 20th Century. Their route is through their own minds and memories. Both travellers are professional historians still tormented by their own unanswered questions. They needed to talk to one another, and the time was short.

This is a book about the past, but it is also an argument for the kind of future we should strive for. Thinking the Twentieth Century is about the life of the mind - and the mindful life.

'Brilliant and disturbing' Yuval Noah Harari

The past is another country, the old saying goes. The same might be said of the future. But which country? For Europeans and Americans today, the answer is Russia.

Under Hitler and Stalin the Nazi and Soviet regimes murdered fourteen million people in the bloodlands between Berlin and Moscow. The killing fields extended from central Polads to western Russia. For twelve savage years, on this bloodsoaked soil an average of one million individuals - mostly women, children and the aged - were murdered every year. Though in 1939 these lands became battlefields, not one of these fourteen million was killed in combat.