Where Good Ideas Come From

by Steven Johnson

For almost a century, the Malthusian epiphany was the canonical story of Darwinism’s roots. But in the early 1970s, a psychologist and intellectual historian named Howard Gruber decided to revisit Darwin’s copious notebooks from the period, reconstructing the elaborate dance of speculation, fact-marshaling, and internal debate that led to Darwin’s breakthrough in the fall of 1838. What Gruber found in the notebooks was a story very different from the account relayed in Darwin’s Autobiography. All the core elements of Darwin’s theory are present in the notebooks well before the Malthusian epiphany, which the notebooks explicitly date at September 28, 1838. Darwin understands the importance of variation; the connection between natural and artificial selection; the competition among different species for survival; the clear physiological connections among species; the epic scale of evolutionary time. All these key concepts are discussed at great length in the notebooks from 1837 on.