Natural selection, statistical mechanics, and the idea of germs were all inspired by social science

It’s only natural to want to hold your scientific field as the most important, or noble, or challenging field. That’s probably why I always present the sciences of human society as the ones that are hardest to do. It’s not so crazy: it is inherently harder to learn about social systems than biological, engineered, or physical ones because we can’t, and shouldn’t ever, have the same control over humans that we do over bacteria, bridges, or billiard balls. But maybe I take it too far. I usually think of advances in social science as advances in what it is possible for science to teach us, and I uncritically think of social science as where scientific method will culminate.
So imagine my surprise to learn that social science isn’t the end of scientific discovery, but a beginning. According to various readings in John Carey’s Faber Book of Science, three of the most important scientific discoveries since the Enlightenment — the theory of natural selection, the germ theory of disease, and the kinetic theory of gasses — brought inspiration from human social science to non-human domains. One of Darwin’s key insights toward the theory of evolution came while reading Malthus’s work on human population. Just in case you think that’s a fluke, Alfred Russell Wallace’s independent discovery of natural selection came while he was reading Malthus. (And Darwin was also influenced by Adam Smith). Louis Pasteur developed the implications of the germ theory of disease by applying his French right-wing political philosophy to animalcules. The big leap there was that biologists rejected that very small insignificant animals could possibly threaten a large and majestic thing like a human, but Pasteur had seen how the unworthy masses threatened the French elite, and it gave him an inkling. Last, James Maxwell, the man right under Newton and Einstein in physics stature, was reading up on the new discipline of Social Statistics when he came up with the kinetic theory of gases, which in turn sparked statistical mechanics and transformed thermodynamics. Physicists have started taking statistical mechanics out of physical science and applying it to social science, completely ignorant of the fact that it started there.
All of these people were curious enough about society to think and read about it, and their social ponderings were rewarded with fresh ideas that ultimately transformed each of their fields.
I think of science as a fundamentally social endeavor, but when I say that I’m usually thinking of the methods of science. These connections out of history offer a much deeper sense in which all of natural science is the science of humanity.
Thanks to Jaimie Murdock and Colin Allen for the connection between Malthus and Darwin, straight from Darwin’s autobiography

In October 1838, that is, fifteen months after I had begun my systematic inquiry, 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 favorable variations would tend to be preserved, and unfavorable ones to be destroyed. The results of this would be the formation of a new species. Here, then I had at last got a theory by which to work.

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