Development of theory
Main article: Development of Darwin's theory
Fearing both scientific and religious criticism, Darwin spent decades developing his evolutionary theories largely in secret.
Darwin was now an eminent geologist in the scientific élite of clerical naturalists, settled with a private income. He had a vast amount of work to do, writing up his findings and theories, and supervising the preparation of the multivolume Zoology, which would describe his collections. He was convinced of the truth of evolution, but for a long time had been aware that transmutation of species was associated with the crime of blasphemy as well as with Radical democratic agitators in Britain who were seeking to overthrow society; thus, publication risked ruining his reputation. He embarked on extensive experiments with plants and consultations with animal husbanders, including pigeon and pig breeders, trying to find soundly based answers to all the arguments he anticipated when he presented his theory in public.
When FitzRoy's account was published in May 1839, Darwin's Journal and Remarks was a great success. Later that year it was published on its own, becoming the bestseller nowadays known as The Voyage of the Beagle. In December 1839, as Emma's first pregnancy progressed, Darwin suffered more illness and accomplished little during the following year.
Darwin tried to explain his theory to close friends, but they were slow to show interest and thought that selection must need a divine selector. In 1842 the family moved to rural Down House to escape the pressures of London. Darwin formulated a short "Pencil Sketch" of his theory, and by 1844 had written a 240-page "Essay" that expanded his early ideas on natural selection. Darwin completed his third Geolo ...