The Rev. Thomas Robert Malthus FRS was an English cleric and scholar, influential in the fields of political economy and demography. Malthus himself used only his middle name Robert.
His An Essay on the Principle of Population observed that sooner or later population will be checked by famine and disease, leading to what is known as a Malthusian catastrophe. He wrote in opposition to the popular view in 18th-century Europe that saw society as improving and in principle as perfectible. He thought that the dangers of population growth precluded progress towards a utopian society: "The power of population is indefinitely greater than the power in the earth to produce subsistence for man". As an Anglican cleric, Malthus saw this situation as divinely imposed to teach virtuous behaviour. Malthus wrote:
That the increase of population is necessarily limited by the means of subsistence, That population does invariably increase when the means of subsistence increase, and, That the superior power of population is repressed, and the actual population kept equal to the means of subsistence, by misery and vice.
Malthus placed the longer-term stability of the economy above short-term expediency. He criticized the Poor Laws, and (alone among important contemporary economists) supported the Corn Laws, which introduced a system of taxes on British imports of wheat. His views became influential, and controversial, across economic, political, social and scientific thought. Pioneers of evolutionary biology read him, notably Charles Darwin and Alfred Russel Wallace. He remains a much-debated writer.
I came to the book with the idea that Mathus was a powerful thinker, but each chapter of the essay served to further disabuse me of this misimpression. Malthus is writing not principally about population, but is instead using his now falsified postulations about population growth to argue that "poor-laws" (wealth redistribution to help England's desperately poor) were making the poor worse off. The arguments are awful. He actually claims that giving X shillings to every poor family will result in an exactly proportionate rise in the cost of the food they'll attempt to buy with it, precisely offsetting the supposed benefit of the redistribution, while pushing other families into dependence as a result of the rise in price. This claim cannot have been thought about seriously before being printed--and so with many other bad arguments made in the service of elite, reactionary opinion.
This is a classic in the field of economics and, by proxy, in ecology and evolutionary biology. Population (and human population, especially) is something I've been interested ever since my first seminar about "the nine billion people problem" regarding lack of sufficient food.
After reading this essay, I realize we are still facing many of the same problems that Malthus outlined in 1798. Population increases exponentially, whereas products of agriculture increase arithmetically. In his time, people often spoke of "unlimited land," where it was assumed that there would always be more land for more crops or more cattle, and people would never exhaust their resource potential. Malthus begged to disagree. The emphasis on manufacturing over agriculture seemed, to him, an inversion of priorities, and yet it is still the case today.
Throughout the essay, he laments this unfortunate relationship of population and food, but ultimately, at the end, he is no closer to a solution. He cites other works, where people have proposed solutions (or outlined their versions of "the future of mankind," whatever use that is), but those have been far less useful than Malthus for a simple reason: his future is not bright, but it is more accurate.
A powerful statement towards the end of the essay reads: "It is, undoubtedly a most disheartening reflection that the great obstacle in the way to any extraordinary improvement in society is of a nature that we can never hope to overcome. ... Yet, discouraging as the contemplation of this difficulty must be ... it is evident that no possible good can arise from any endeavours to slur it over or keep it in the back ground. On the contrary, the most baleful mischiefs may be expected from the unmanly conduct of not daring to face the truth because it is unpleasing. ... But if we proceed without a thorough knowledge and accurate comprehension of the nature, extent, and magnitude of the difficulties we have to encounter, or if we unwisely direct our efforts towards an object, in which we cannot hope for success, we shall not only exhaust our strength in fruitless exertions and remain at as great a distance as ever from the summit of our wishes, but we shall be perpetually crushed by the recoil of this rock of Sisyphus."
Terrible work, poorly argued. If you're studying the history of Malthusian arguments then reading this makes sense, but otherwise you'd do well to look for more modern works which use something resembling logic or statistics. Malthus' primary contention—that population increases geometrically while sustenance increases arithmetically—is basically supported by a tautology and no real evidence. Throughout the book he relies on racist second-hand stories of other cultures or patriarchal notions of the one true way society is structured (his argument that marriages parallel birth rate was never valid, not then and not now). It's no surprise history has badly disproven Malthus' argument seeing as it was based on wild assumptions. What's more, his whole argument isn't very generalizable, being caught up in the debates of the day with figures like Godwin. It makes for irrelevant, inaccurate reading today.