Thomas Malthus and Charles Lyell were two figures who influenced Darwin's theories.
Malthus was an influence through his book on the population principle. Darwin had a
parallel thinking in the concept of individual struggle in natural selection. Lyell's
influence on Darwin was from his book "Principles". Darwin agreed with Lyell's
uniformitarian theories, and the uniformitarian understanding helped Darwin explain the
elements of natural selection.
Malthus believed that starvation would always be a part of human life because he thought
that population would increase at a greater rate than food supply. In his book, "Essay on
the Principle of Population", he discussed eliminating help for the poor. He thought this
would be a natural way of getting rid of poverty and stopping the poor from reproducing
more poor people. Malthus also explained that competition was best for all in human
societies and man would always have to struggle to feed himself and his family. Another
way Malthus viewed the population principle was as something brought on by God as a
way to prevent man from being lazy and to make man work hard to support his family.
Darwin derived the concept of the struggle for existence in part from Malthus's essay. He
believed that creatures less fit for their environment would tend to die off. This would be
called the struggle for existence. Some people thought that nature was a balanced system,
but Darwin saw it as a mechanism. He believed the creatures that were best adapted
would survive. Although Darwin agreed with Malthus on the struggle of individuals, he
differed in opinion on Malthus's idea of the increase of population. Darwin (just from
observation) did not believe that population would increase at a tremendous rate from
year to year but believed it would stay somewhat constant.