Illustration of Population pressure

1798 Population pressure

The book of science

Tom Sharp

Thomas Robert Malthus demography Illustration of Population pressure

Population pressure

“Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio.” Simple mathematics and his convictions as a retired Anglican clergyman led Thomas Robert Malthus to assert that natural or “positive” checks to overpopulation increase the death rate, but that “preventive” checks could reduce the birth rate. Malthius advocated the education of the lower class about voluntary abstinence. This began the study of principles and mechanisms that influenced social scientists and politicians and ended the dole in eighteen thirty-four leaving the old, the sick, and the poor to die in the streets.

Pressure of liberty

Have we finally learned violence can not solve problems? Have we learned other people are human like ourselves? Evidence to the contrary— our wars and armaments our tariffs and border security our nationalism and tribalism our hatreds and fears. Infant mortality, epidemics, famines, natural disasters, emigration, repression, wars, genocides, terrorism, and other crimes against humanity are harsh measures but do the job that good people like ourselves can’t take responsibility for. Other people are free to mess up their own lives but not to mess with us.


Assuming people continue to act as they have acted our population on this planet would continue to grow. Assuming science and agriculture could keep ahead of our needs if only distribution were equitable although we know distribution is never equitable, then we will not need to practice genocide or infanticide or watch others cruelly suffer or eat each other; however, we may need to continue to ignore evidence of inhumanity and ignorance leading to misery and evil as our best efforts to help continue to fall short.

Wouldn’t it be enough for each couple to have only one child? The grand one-child policy in China shows it is not only not enough, but that there are unanticipated problems. Many other states lack the will, the means, or the control, so the world population continues to grow.

Reading Malthus’s book on Population and appreciating “the struggle for existence” described in it, Darwin was inspired in 1838 to think of the fundamental theory of the descent of the species: “it at once struck me that under these circumstances favorable variations would tend to be preserved and unfavorable ones to be destroyed. The result of this would be the formation of new species.”

See also in The book of science: