Demography as a discipline was founded, at least in the English-speaking world, by a theory of scarcity. The Reverend Thomas Malthus (1766-1834) argued in the first edition of his Essay on the Principle of Population (1798) that two great forces were in contention and had been throughout the existence of humans: the unstoppable force of population growth on the one hand pressing against the immovable – or at best only slowly moving – force of resource constraints on the other.

Imagine that each woman on average bears six children. This is roughly what we might expect in a world in which most women engage in sexual intercourse more or less regularly throughout the period of their fertility and not using any form of contraceptive. Some women will of course have far more children: I once knew one who had had fifteen. And some will have none. But six is around what we would expect to be a natural average. Women are only half the human race, and a man is required for each child. So two people will become six, normally in an average of around twenty-five years, with some of the children being born earlier in a woman’s lifetime, some later. Now if two becomes six in twenty-five years then six becomes eighteen in fifty. Eighteen become fifty-four in seventy-five years and by the end of the century, fifty-four have become one hundred and sixty-two.

This is of course a simplification. Age cohorts live side by side with older and younger cohorts and the exact size of a population will depend on the size of the different age cohorts and, in turn, on how long each cohort lives. But looking at the size of a single cohort gives us a vivid sense of the population growth and this simplification will suffice for our purposes.

If we accept the critical numbers of six children per woman and of twenty-five years per generation – that is, four generations per century – then we can see just how fast, in unconstrained circumstances, the human population would grow. Around the year 1 AD it is estimated that there were around 250 million people in the world.¹ With a trebling per generation and four generations per century, the number of humans would have risen to current population of the world of around eight billion in just seventy-five years!² But instead of this happening over seventy-five years, it took around two thousand. Why on earth was that?

Malthus’s problem and his answer were simple, brilliant and, once revealed, obvious. The world in 75 AD simply did not have the capacity to feed eight billion. Had the kind of population growth discussed above continued, by the year 200 ad the population of the world would have been 2,000 billion. Even with today’s technology, such a thing would be unthinkable. Starvation would finish most of us off very quickly. With the technology of 200 AD this is even more the case. There was never any chance of it happening.

The truth is that although there is this strong and exponential power of population to increase, resource constraints come to bear. These result in death and, particularly, in early death. In most societies throughout most of time, a quarter or a third of babies die within the first year of their lives. Two thirds of those born fail to make it to or through their reproductive years. In times of good harvests, peace and the absence of pandemics, a population can indeed grow, as it did in Europe during the early and high Middle Ages. But it can grow only so far. If war and disease do not knock populations back then famines will, for the earth can simply feed only so many. The picture portrayed by Malthus, at least in the early editions of this work, was a bleak one. Human sexual instincts would persist, population growth would be the natural outcome, and humans would live forever pressing up against the ability of the planet to sustain them. Only a small share of those born would survive to become parents themselves.

A clergyman of the Church of England, Malthus disdained any form of birth control – primitive as it was in his day – and believed that the only solution was for men to restrain their sexuality until such time as they could afford to support a family. The only alternative to a world of want and hunger was a world of sexual repression.

Malthus’s theory was originally established in opposition to eighteenth-century Enlightenment thinkers such as the Marquis de Condorcet and William Godwin. Contrary to their optimism and belief that a just and perfect society could be constructed, it turned out that the poor would, after all, always be with us, as the Bible had foretold (Mark 14:7). The less sexual restraint was exercised, Malthus argued, the more poor there would be. Malthus and his friend the economist David Ricardo were the principal targets of the essayist Thomas Carlyle when he spoke of economics as ‘the dismal science’. Malthusian political economy was the political economy of want, need and scarcity.

Malthusian thinking deeply embedded itself into the Victorian outlook and heavily influenced the era’s policymakers and public intellectuals, at least in the United Kingdom and the British Empire. At home the reform of the poor law, abroad the indifference of famines from Ireland to India were at least in part shaped by a belief that compassion would be misplaced and that, given that only so much food could be created, many were bound to go hungry. Indulging them would keep them alive and grow their numbers only to create more intense misery. Generations of public officials and administrators were informed by this mindset.

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