In 1832, Charles Knowlton published The Fruits of Philosophy, a pamphlet advocating for controlling reproduction and detailing methods for preventing pregnancy. Originally published anonymously in Massachusetts, The Fruits of Philosophy was an illegal book because United States law prohibited the publishing of immoral and obscene material, which included information about contraception. In The Fruits of Philosophy, Knowlton detailed recipes for contraceptives and advocated for controlling reproduction. In 1877 in Europe, social activists Charles Bradlaugh and Annie Besant republished the pamphlet in London, England. At that time, many governments, including the United Kingdom, still considered the book illegal material due to its discussion of contraception. The Fruits of Philosophy was one of the first publications detailing contraceptive methods for controlling reproduction and activists used it in some of the first attempts at repealing obscenity laws in the United States and Great Britain. Through their efforts, Knowlton and those who later republished the pamphlet increased knowledge of reproduction and awareness of methods of contraception. By challenging anti-obscenity laws, the author and activists also helped with the eventual weakening and dissolution of such law.