The evolutionary biologist Julian Huxley (1887-1975) attempted to promote a "religion for the future," which he would come to refer to as Transhumanism. Transhumanism was an attempt to unite a more traditional humanistic view of the human as containing some form of core essence or potential with an evolutionary point of view of humans as a work in progress. Before humans, natural selection had been responsible for the transformation of life. Through its ordering principles and through chance, it had given rise to humankind, which had ushered in a new phase of evolution. Humanity stood on the threshold of yet another critical point in evolution: The consciously purposive phase of evolution. This open access book explores the history of transhumanism by analyzing how Julian Huxley's transhumanism develops and why it does at this particular point in time, by placing it firmly within the context of his specific scientific and sociopolitical milieu, starting roughly in the interwar years and stretching over the Second World War to the 1970s. Continuing, the study then focuses on the new transhumanists of the 1970s, 1980s and 1990s and investigates continuity in mode of thinking, contributing to a more coherent understanding of transhumanism, its history and of modern projects of human enhancement. The book captures how scientific and technological development in relation to society and social order shapes images and expectations of the future and of what future is desirable.