There's a fine article at Spiked by Tim Black exposing what Robert* Malthus actually said. Malthus was a reactionary nostalgic pessimist who was not just wrong about population growth outstripping food supply. He was also wrong in his cynicism about helping the poor lest they breed more.
(*Everybody calls him Thomas these days, whereas his contemporaries all called him Robert, which was his second name. Calling him Thomas is like calling the first director of the FBI John Hoover.)
His subject was not so much the principle of population growth - this Malthus was happy to take for granted, hence the scant attention he actually paid to justifying it. Rather, his real purpose was the extent to which a supposed law of population would confound those writers like Godwin and Condorcet who advocated social transformation. The theory, the so-called science, was always subservient to Malthus's main objective of justifying the social order as it is. As Malthus himself wrote: 'The principal argument of this Essay only goes to prove the necessity of a class of proprietors, and a class of labourers.' Malthus was not pessimistic about the chances of improving society because of his theory of population - that is the wrong way round. His wilful social pessimism, where misery was the lot of the majority, inspired his theory of population.
...The Essay is at the very least a striking attempt to smother society as it then was in amber, to fix it permanently in time. The forces that would revolutionise society, from the burgeoning industrial bourgeoisie to the incipient class consciousness of the proletariat, threaten Malthus's world on either side. He wants to hold these social forces back, to paint them as tending against the natural order of things. This was what was always animating the essay, not some scholarly concern with population growth and agricultural productivity: a desire to render society, in all its vice and misery, as the product of the laws of nature. The Essay was a stunning work of reaction, a desperate rear-guard move from a man who, at some level, knew the tide of history was rushing against him. For there is nothing more desperate than blaming hunger and want on the excessive breeding of the 'race of labourers'.
Today's neo-Malthusians generally think of themselves as leftish progressives. But their hero was a dogmatic conservative. There is a pattern here. Neo-Malthusians also tend to hero-worship Garret Hardin, the author of "The Tragedy of the Commons" article in Science (1968).
I met Hardin once and found him a reactionary anti-immigration conservative. So I went and read the famous article right to the end, which I had not done before and was shocked to find that its famous bit, about the mismanagement of common property, is just a brief prelude to a diatribe about coerced population control:
Coercion is a dirty word to most liberals now, but it need not forever be so. As with the four-letter words, its dirtiness can be cleansed away by exposure to the light, by saying it over and over without apology or embarrassment. To many, the word coercion implies arbitrary decisions of distant and irresponsible bureaucrats; but this is not a necessary part of its meaning. The only kind of coercion I recommend is mutual coercion, mutually agreed upon by the majority of the people affected.
The most important aspect of necessity that we must now recognize, is the necessity of abandoning the commons in breeding. No technical solution can rescue us from the misery of overpopulation. Freedom to breed will bring ruin to all. At the moment, to avoid hard decisions many of us are tempted to propagandize for conscience and responsible parenthood. The temptation must be resisted, because an appeal to inde- pendently acting consciences selects for the disappearance of all conscience in the long run, and an increase in anxiety in the short.
The only way we can preserve and nurture other and more precious freedoms is by relinquishing the freedom to breed, and that very soon. "Freedom is the recognition of necessity"-and it is the role of education to reveal to all the necessity of abandoning the freedom to breed. Only so, can we put an end to this aspect of the tragedy of the commons.