Hans Jonas was a German-born philosopher who was, from 1955 to 1976, Alvin Johnson Professor of Philosophy at the New School for Social Research in New York City.
Jonas' writings were very influential in different spheres. For example, The Gnostic Religion, first published in 1958, was for many years the standard work in English on the subject of Gnosticism.
The Imperative of Responsibility (German 1979, English 1984) centers on social and ethical problems created by technology. Jonas insists that human survival depends on our efforts to care for our planet and its future. He formulated a new and distinctive supreme principle of morality: "Act so that the effects of your action are compatible with the permanence of genuine human life".
While The Imperative of Responsibility has been credited with catalyzing the environmental movement in Germany, his work The Phenomenon of Life (1966) forms the philosophical undergirding of one major school of bioethics in America. Murray Bookchin and Leon Kass both referred to Hans Jonas's work as major, or primary, inspiration. Heavily influenced by Heidegger, The Phenomenon of Life attempts to synthesize the philosophy of matter with the philosophy of mind, producing a rich existential understanding of biology, which ultimately argues for a simultaneously material and moral human nature.
His writing on Gnosticism interprets the religion from an existentialist philosophical viewpoint. Jonas was the first author to write a detailed history of ancient Gnosticism. He was also one of the first philosophers to concern himself with ethical questions in biological science.
Jonas's career is generally divided into three periods defined by the three works just mentioned, but in reverse order: studies of gnosticism, studies of philosophical biology, and ethical studies.