Debates about Malthus: the two-card and three-card trick

December 22, 2011 • Daily Email Recap

Thanks to Mark O’Connor of Australia for this fascinating analysis.

Debates about Malthus: the two-card and three-card trick

There has been a view, much put about by rightwing pro-business think-tanks,  that Malthus was a gloomy pessimist from whose story we should learn not to listen to “pessimists”. This view is  is now looking very shaky as famine stalks more and more countries. Journalistic articles are beginning to appear that use as their opening “peg” the remark that Malthus may not have been such a false prophet as we all assume.

In fact scholars and reputable encyclopedias never did so assume — that claim was wishful thinking by those with their own reasons for wanting to believe population growth is not a problem.

Just lately  there has been much  interest in the researcher Alison Bashford’s study of Malthus. She emphasises the importance of 10 chapters that have traditionally been omitted from reprints of his 1803 Essay on the Principle of Population, and claims the missing chapters show his thinking in a new light. See

I’m not getting too excited about this argument, since the Essay, even  in its traditionally abbreviated form, was (for its day) an impressive piece of work. And scholarly information is of limited value in dealing with the propagandists of the growth lobby. When they talk of Malthus, they are not interested in scholarly precision, and not fond of reading his works closely. They have two simple (and quite invalid) arguments that they use; and anyone debating with them needs equally brief refutations to these.

I call their two arguments the two-card trick and the three-card trick.

The two-card trick is a simple two-stage argument (or syllogism):

1.     Malthus is the greatest and most famous expert on the supposed dangers of population growth. He prophesied that population growth would lead to famines, which did not come true.

2.      Therefore all later warnings, no matter by how many eminent experts, that famines or other disasters due to population growth may happen, or will probably happen (or are already happening) will not come true and should be ignored.

This is an obviously fallacious argument. One might as well say, “Eminent seismologists have warned of tsunamis that did not occur; therefore no one should heed such warnings”.  The logical fallacy, reduced to a syllogism, is of the form:  “My horse is grey. Therefore all horses are grey.”

Of course the cleverer growth lobbyists realize that if they present this argument as a syllogism, its logical flaw will be noted. Their skill is to disguise the logic, and make a great parade of talking about, say, the fruits of historical experience, what we can learn from the case of Malthus, etc.

In replying to the two-card argument, I always point out the main logical error first. Then I go on to point out a second logical flaw: If in fact Malthus is simply a man who made a spectacular mistake, why are you buttering him up, representing him as pre-eminent in the field, and implying that he is more likely to be right than the modern experts you seek to discredit?  Have demographers and agricultural experts learnt nothing since his day? And have there been no improvements in our ability to gather data and to observe global patterns? Would you argue “The founders of modern medicine used to deny the heart pumped blood, so why should I believe my cardiologist?”

Also, did Malthus in fact prophesy, or merely warn? (In which case the first card is as false as the second). And then, how specific were his predictions of human numbers exceeding food supply, and how often has what he warned about in fact occurred?  Would you refuse to believe eye-witness accounts of famines on the grounds that someone once predicted a famine or famines that didn’t occur?

By the time I’ve run though these points, and then suggested the opposition should apologise for using this misleading argument, they tend to look “tolerably foolish”.  But note that it is important to start with the two good-as-gold logical points: that one prophet being wrong doesn’t mean all prophets are wrong, and that if Malthus was simply the false prophet they claim, he would not deserve the pre-eminence they have pretended to give him.

But if you start instead with the last point, and defend Malthus by saying that he wasn’t necessarily prophesying and wasn’t necessarily wrong, it will sound like you are defending a weak point in your own position. They will then contest your defence of Malthus, and you will find yourself in the glue-pot, since the more you defend Malthus the more you will seem to be conceding their basic (and illogical) contention, that unless Malthus can be exonerated, no subsequent prophesy or even observation of famine should be believed. Target that absurdity first, and then mop up the minor dishonesties at leisure.

Incidentally, the main reason Malthus’s expectation of continuing famines in the UK (as future population outstripped future food supply) did not come true, is that during and after the Napoleonic wars Britain and France emerged as pre-eminent colonial powers, and proceeded to bleed each other white of young men. They did this via a long series of land battles and sea battles, not to mention the practices of sending troops and bureaucrats to tropical colonies where they died like flies. Since in those days single women tended not to have babies, population growth was much reduced. As well, relations with the United States improved, so that even though the US was lost as a colony, it obligingly took off a substantial proportion of the UK’s population (including the Irish who were starving after the potato famine)  as emigrants.  Further Britain happened to emerge as the dominant colonial power, and with complete control of the seas, and so could afford to import food from other countries — which to this day is the only thing that keeps its bloated population from starving. It was not improvements in C19th agriculture that kept up with population growth and prevented  the Malthusian famines occurring; it was the combination of death in war, death from colonial diseases, and massive emigration to North America.  This unlikely combination of factors was not inevitable, and could not in Malthus’s day have been given a high probability of coming true.

But don’t waste your breath explaining all this to those who don’t want to know.

The three-card trick is a more elaborate version of the two-card. It goes like this:

1.     Thomas Malthus was the first or at least the greatest thinker to argue that population growth tends to outgrow food and resources. (Largely true).

2.     Malthus was a pessimistic false prophet who prophesied a famine the British never experienced. (Grossly unfair, as any good encyclopedia article on Malthus will show. If that was all he was, he would not be the most famous thinker on the subject, and the three-card trick would collapse at this point. In fact Malthus did not claim to know the future, and he did not so much predict a future famine as provide an intelligent account of existing famines — and of reasons they were likely to recur.)

3.     Therefore those warning of famine today are minor Malthuses, and even less worthy of respect. (Note that even if the second card was valid, the conclusion would still be clearly invalid.)

In the debate-book on population that I am currently (late 2011) writing for Pantera Press, called Big Australia Yes/No?, my opponents are two “fellows” from the rightwing Centre for Independent Studies. Their beguilingly gentle version of the three-card trick begins: Thomas Malthus, an early 19th century English philosopher, famously said that unchecked population growth would lead to worldwide famine and disaster. Two hundred years later, entrepreneur Dick Smith is running a similar line . . .

In a brief right of reply, my comment, which may or may not survive the editing and compression process, is that they may have been innocently misled into repeating this nonsense, but they should now distance themselves from it, and apologise. World hunger is not an issue to dismiss with such glibness.

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