We like to think of war as a temporary breakdown, an interruption in our normally peaceful existence. But what if it isn't? What if it's an innate and inescapable aspect of humanity? In her series of BBC Reith Lectures (The Mark of Cain), historian Margaret MacMillan ponders whether we're destined to fight, and explores our very complicated feelings about war.

In her first lecture she explores the origins of war and its dark paradox: that it can also bring progress. Lecture 1 is called War and Humanity.

There are endless thoughtful and passionate quotes about the futility of war, about the need to end war and why we must return to what we imagine is humanity's natural state: peace.

But Professor MacMillan says:

"We like to think of war as an aberration, as the breakdown of the normal state of peace. This is comforting but wrong. War is deeply woven into the history of human society. Wherever we look in the past, no matter where or how far back we go, groups of people have organized themselves to protect their own territory or ways of life and, often, to attack those of others. Over the centuries we have deplored the results and struggled to tame war, even abolish it, while we have also venerated the warrior and talked of the nobility and grandeur of war. We all, as human beings, have something to say about war."

She delivered her first lecture at the BBC Radio Theatre in London. A question and answer session after the lecture included thoughts and insights from other historians, as well as an Admiral, a General, and a news correspondent who covered the Falklands War in 1982.

Margaret MacMillan is emeritus professor of international history at Oxford University and professor of history at the University of Toronto. Her acclaimed books include Paris 1919: Six Months That Changed the World (Random House, 2003), The War That Ended Peace: The Road to 1914 (Penguin Canada, 2014), and her Massey Lectures History's People (House of Anansi, 2015).

For copyright reasons, we cannot provide this episode as a podcast. But the BBC Reith Lectures website offers additional ways of listening to Margaret MacMillan's series. There are also complete transcripts of all five lectures, as well as details on previous Reith series.