Your ideas are the sum of your influences. This is something I first came across in Steven Johnson's Where Good Ideas Come From:
“ideas are works of bricolage; they’re built out of that detritus. We take the ideas we’ve inherited or that we’ve stumbled across, and we jigger them together into some new shape.”
And it's this concept, what Steven Johnson calls the "adjacent possible", that kept coming to mind as I read Paul Johnson's brilliant, short biography of Charles Darwin.
The story is packed with Darwin's influences, from Malthus to Lyell, and, of course, The Beagle. These are the dots that Darwin eventually joined in his scientific work.
"At intervals in the five-year voyage, Darwin was able to spend a total of three years and one month on land, traveling widely... He shot a wide variety of birds and animals, went on an ostrich hunt, studied the effects of a large-scale earthquake, observed a major volcanic eruption, and visited at length tropical rain forests, high mountains, sierras, pampas and other grasslands, rivers, lakes, and a wide variety of scrub and brushwood areas, as well as scores of native villages, settler towns, mines, and cities."
As we can see from that one passage, Darwin was voracious. In an age of specialisation, its easy to forget that people like Darwin dabbled, slowly expanding horizons and building up the bricolage.
"In 1838 he came across... Malthus's Essay on Population... This had a huge emotional impact on him, equivalent to the ones he had felt when he first experienced the savages of Tierra del Fuego..."
"He liked to have several projects going at once and switch from one to another as the spirit or the excitement generated by results moved him - from zoology to botany to physiology or anthropology, from insects to plants, the invertebrates, to men, and back to insects again."
The voracity of the ideas doesn't even seem to matter. Even in Darwin and Malthus' day, the evidence was against Malthus' Iron Law of Population. But it inspired something else and was reworked. The important point is to be open to fresh thinking.
"Darwin was a polymath. It was his great strength. Without the breadth as well as the depth of his knowledge, it is doubtful whether Origin could have succeeded.
This is a great, short intro to Darwin. Although, it will probably leave you wanting more. If anyone has any suggestions for a longer Darwin bio I'm all ears.