In this new series for BBC Radio 3, historian Tristram Hunt rediscovers the stories of three ideas that emerged in Britain - and then traces how their impact has spread far beyond our shores.
In the first programme, Tristram explores how the insight of the great British economist, the Reverend Robert Malthus (1766-1834), wreaked havoc in 19th century India - and yet was later adopted by Indians themselves. Malthus argued that the number of people in the world will always tend to increase faster than the supply of food to feed them. The only way to prevent this was to act to lower the birth rate. Or to wait for famine, war and disease to intervene.
Tristram begins in Hertfordshire, among the elegant quadrangles of what was once the home of the East India Company's training college. Here, he discovers, Malthus taught for almost thirty years, shaping the worldview of future colonial governors. But soon he follows the trainees' journey to India. When famines began to strike India in the later 19th century, many administrators responded on Malthusian lines. Famine was inevitable. Spending a fortune to save lives was at best a "necessary evil".
In Delhi, Tristram visits the site of the astonishing 1877 'Durbar', an eye-popping display of Imperial grandeur - which began just as news was emerging of a terrible famine in southern India. And he discovers how, amid a week-long feast for thousands of dignitaries, one senior British administrator was dispatched south. His mission: to stop the regional government spending too much money on famine relief.
From there, Tristram travels to Chennai (formerly Madras) to learn about the apocalyptic horror the region endured, at the cost of millions of lives. He listens to a Tamil folk song which mourns the suffering of people driven to dig up roots and give away their children in their struggle to survive. And then - astonishingly - he discovers how Malthus' ideas were taken up by Indians themselves, from campaigns for contraception in the 1930s to the coercive sterilisation campaigns of the 1970s.
But finally Tristram asks whether the malign uses to which Malthus has been put mean that his basic idea can be safely ignored? Or is the ongoing growth of the world's population a serious issue that urgently needs our attention, for the good of everyone?
With Professor David Arnold, Dr Minoti Chakravatry-Kaul, Dr David Hall-Matthews, Dr Chandrika Kaul, Professor A.R. Venkatachalapathy, Associate Professor S. Anandhi, Professor Mohan Rao, Sir Jonathon Porritt.
PRESENTER: Tristram Hunt MP
PRODUCER: Phil Tinline.