controversy frustrated him for years. Anti-vaccination campaign In the early 1880s, Wallace joined the debate over mandatory smallpox vaccination. Wallace originally saw the issue as a matter of personal liberty; but, after studying statistics provided by anti-vaccination activists, he began to question the efficacy of vaccination. At the time, the germ theory of disease was new and far from universally accepted. Moreover, no one knew enough about the human immune system to understand why vaccination worked. Wallace discovered instances where supporters of vaccination had used questionable, in a few cases completely false, statistics to support their arguments. Always suspicious of authority, Wallace suspected that physicians had a vested interest in promoting vaccination, and became convinced that reductions in the incidence of smallpox that had been attributed to vaccination were due to better hygiene and improvements in public sanitation. Another factor in Wallace's thinking was his belief that, because of the action of natural selection, organisms were in a state of balance with their environment, and that everything in nature, even disease-causing organisms, served a useful purpose; he feared vaccination might upset this balance. Wallace pointed out that vaccination, which at the time was often unsanitary, could be dangerous. In 1890, Wallace gave evidence to a Royal Commission investigating the controversy. It found errors in his testimony, including some questionable statistics. The Lancet averred that Wallace and other activists were being selective in their choice of statistics. The commission found that smallpox vaccination was effective and should remain compulsory, though they recommended some changes in procedures to improve safety, and that the penalties for people who refused to comply be made less severe. Years later, in 1898, Wallace wrote a pamphlet, Vaccination a Delusion; Its Penal Enforcement a Crime, attacking the commission's findings. It, in turn, was attacked by The Lancet, which stated that it repeated many of the same errors as his evidence given to the commission. Legacy and historical perception Honours As a result of his writing, Wallace became a well-known figure both as a scientist and as a social activist, and was often sought out for his views. He became president of the anthropology section of the British Association in 1866, and of the Entomological Society of London in 1870. He was elected to the American Philosophical Society in 1873. The British Association elected him as head of its biology section in 1876. He was elected to the