Theodore John Kaczynski (May 22, 1942 – June 10, 2023), also known as the Unabomber, was an American mathematician and domestic terrorist. He was a mathematics prodigy but abandoned his academic career in 1969 to pursue a more primitive life. Between 1978 and 1995, Kaczynski killed three people and injured 23 others in a nationwide mail bombing campaign against people he believed to be advancing modern technology and the destruction of the environment. He authored Industrial Society and Its Future, a 35,000-word manifesto and social critique opposing industrialization, rejecting leftism, and advocating for a nature-centered form of anarchism.