Thomas Malthus biography - theory
An Essay on the
Principle of Population
Thomas Malthus was born near Guildford, Surrey, England in 1766
into a well-off family. He was educated from 1784 at Jesus
College, Cambridge where he achieved distinguished marks in his
mathematical studies. He was subsequently ordained as an Anglican
cleric in 1797 despite having an inconvenient speech impediment.
He became curate of the parish of Albury in Surrey in 1798 and
held this post for a short time.
His main contribution is to Economics where a theory,
published anonymously as "An Essay on the Principle of
Population" in 1798 has as a central argument that populations
tend to increase faster than the supply of food available for
To quote directly from the essay:-
"Population, when unchecked, increases
in a geometrical ratio. Subsistence only increases in an
arithmetical ratio. A slight acquaintance with numbers will show
the immensity of the first power compared to the
The essay thus anticipated that this propensity could only lead
to real distress:-
" The number of labourers also being
above the proportion of work in the market, the price of labor
must tend towards a decrease; while the price of provisions would
at the same time tend to rise".
This theory of the effective inevitability of poverty and
distress contradicted the optimistic belief prevailing in the
early 19th century, that a society's fertility would lead to
economic progress and helped to give Economics, then more
frequently known as "Political Economy" the alternative name of
"The Dismal Science."
Earlier that year the British statesman William Pitt had
proposed that poor relief should give special consideration to
the encouragement of large families as "those who, after
having enriched their country with a number of children, have a
claim upon its assistance for their support." In the event
Malthus's theory was often used as an argument against efforts to
better the condition of the poor.
Malthus later went so far as to suggest that, for the
lessening of the probability of a miserable existence for the
poor, it was advisable to seek to cut the birth rate in society.
This suggestion was unmistakably outrageous given the moralities
of the times (and would doubtless be most controversial
The Essay on the Principle of Population and other writings
encouraged the first systematic demographic studies and also had
a significant influence in several ways:-
In Economics David Ricardo's, "iron law of wages" and theory
of distribution of wealth contain some elements of Malthus'
Thomas Malthus Essay
Of far more dramatic significance is the fact that both
Charles Darwin and Alfred Russel Wallace admitted that the food
scarcities regarded as being normal by Malthus had been of
KEY influence on their seperate development of theories of
the evolutionary Origin of Species.
Charles Darwin and
Alfred Russel Wallace
To use Charles Darwin's own words from his Autobiography speaking about a time late in 1838 when
Malthus ideas were of the utmost importance in guiding the future direction of his own thinking:-
I happened to read for amusement Malthus on 'Population', and being well prepared
to appreciate the struggle for existence which everywhere goes on from long-continued observation
of the habits of animals and plants, it at once struck me that under these circumstances favourable
variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this
would be the formation of a new species. Here, then, I had at last got a theory by which to work.
Words from another Autobiography, this time one by Alfred Russel Wallace, are also available to us as
evidence of the massively significant influence of Thomas Malthus Essay on the
Principle of Population.
It was in 1858 whilst he was laid up with a malarial fever at Ternate, in the
Celebes Islands, that a possible solution to the method of evolution flashed into form in Wallace's mind.
The outcome being that this burst of inspiration together with his more longstanding ruminations
resulted in Alfred Russel Wallace independently framing a theory of the evolutionary origin of
species by natural selection.
At the time in question I was suffering from a sharp attack of intermittent fever, and every day during the cold and succeeding hot fits had to lie down for several hours, during which time I had nothing to do but to think over any subjects then particularly interesting me. One day something brought to my recollection Malthus's "Principles of Population", which I had read about twelve years before. I thought of his clear exposition of "the positive checks to increase" - disease, accidents, war, and famine - which keep down the population of savage races to so much lower an average than that of more civilized peoples. It then occurred to me that these causes or their equivalents are continually acting in the case of animals also; and as animals usually breed much more rapidly than does mankind, the destruction every year from these causes must be enormous in order to keep down the numbers of each species, since they evidently do not increase regularly from year to year, as otherwise the world would long ago have been densely crowded with those that breed most quickly. Vaguely thinking over the enormous and constant destruction which this implied, it occurred to me to ask the question, Why do some die and some live? And the answer was clearly, that on the whole the best fitted live. From the effects of disease the most healthy escaped; from enemies, the strongest, the swiftest, or the most cunning; from famine, the best hunters or those with the best digestion; and so on. Then it suddenly flashed upon me that this self-acting process would necessarily improve the race, because in every generation the inferior would inevitably be killed off and the superior would remain - that is, the fittest would survive. Then at once I seemed to see the whole effect of this, that when changes of land and sea, or of climate, or of food-supply, or of enemies occurred - and we know that such changes have always been taking place - and considering the amount of individual variation that my experience as a collector had shown me to exist, then it followed that all the changes necessary for the adaptation of the species to the changing conditions would be brought about; and as great changes in the environment are always slow, there would be ample time for the change to be effected by the survival of the best fitted in every generation. In this way every part of an animal's organization could be modified exactly as required, and in the very process of this modification the unmodified would die out, and thus the definite characters and the clear isolation of each new species would be explained. The more I thought over it the more I became convinced that I had at length found the long-sought-for law of nature that solved the problem of the origin of the species. For the next hour I thought over the deficiencies in the theories of Lamarck and of the author of the "Vestiges," and I saw that my new theory supplemented these views and obviated every important difficulty. I waited anxiously for the termination of my fit so that I might at once make notes for a paper on the subject. The same evening I did this pretty fully, and on the two succeeding evenings wrote it out carefully in order to send it to Darwin by the next post, which would leave in a day or two.
And so it was that Wallace sent a memoir about this
evolutionary theory to the influential expert
naturalist Charles Darwin, arrived in Darwin's hands in June 1858. In a covering letter Wallace asked that Darwin forward the memoir to a famous scientist, Sir Charles Lyell,
if Darwin thought the content merited his attention.
I wrote a letter to him in which I said I hoped the idea would be as new to him as it was to me, and that it would supply the missing factor to explain the origin of the species. I asked him if he thought it sufficiently important to show it to Sir Charles Lyell, who had thought so highly of my former paper.
From Alfred Russel Wallace : My Life, pp. 360-363.
Darwin had not intended to publish his own
theorisings but this approach by Wallace forced his hand. The unfolding scenario in which these events took place are more fully
considered on our biographical pages about Alfred Russel Wallace and about Charles Darwin.
From 1805 until his death Thomas Malthus was Professor of
Modern History and Political Economy at the newly established
college of the East India Company at Haileybury. This appointment
may have been the first professional post in Economics held by
anyone in human history.
Other works include An Inquiry into the Nature and Progress of
Rent (1815) and Principles of Political Economy (1820).