Prominent authors elaborating a critique of technology are, e.g. Jacques Ellul, Ivan Illich, Langdon Winner, Joseph Weizenbaum, Theodore Roszak, Günther Anders, Neil Postman, Martin Heidegger and Lewis Mumford. Some authors such as Chellis Glendinning and Kirkpatrick Sale consider themselves Neo-Luddites and hold that technological progress has had a negative impact on humanity.