What insight did Darwin gain from reading Thomas Malthus’s essay on human suffering?

Reading Malthus's essay on human suffering had a profound impact on Darwin's thinking about the natural world. The essay convinced him that competition for resources was a fundamental aspect of human life, and he saw this same pattern in the natural world. Malthus argued that human population growth would inevitably lead to resource scarcity, which would then result in suffering and competition. Darwin realized that a similar dynamic existed in nature, where organisms must compete for limited resources like food, water, and shelter. He saw that only the fittest and most adaptable individuals would be able to survive and reproduce in these conditions.

This idea became a key component of Darwin's theory of evolution by natural selection. According to this theory, organisms that are better adapted to their environment are more likely to survive and pass on their genes to the next generation. In other words, those individuals who are best equipped to compete for resources are the ones who will be the most successful in propagating their genes. As Darwin wrote in his notebook in 1838, "The law of Malthus applies with peculiar force to the whole animal and vegetable kingdoms, as may be shown by observing the greater power of increase of many animals compared with their means of subsistence."

In addition to providing insights into the workings of nature, Malthus's essay on human suffering helped Darwin to reconcile the existence of suffering with the idea of a benevolent creator. Malthus argued that suffering was a natural consequence of the laws of nature and that there was no need to invoke a malevolent or indifferent deity to explain it. This idea resonated with Darwin, who struggled with the problem of evil and the question of why a loving God would allow so much suffering in the world. By viewing suffering as a natural consequence of the struggle for existence, Darwin was able to reconcile his scientific observations with his religious beliefs.