The desire to improve upon the human existence isn't new. People have always wanted to expand the boundaries of the human condition, whether by seeking immortality or supreme happiness and health. From the Mesopotamian King Gilgamesh, to Spanish explorer Ponce de Leon, to French writer and philosopher Voltaire, people have sought out extensions to human life (and even immortality). Some have gone down the path of science, pushing for medical breakthroughs to bring about longer life spans. Others have gone after legends such as the Fountain of Youth. But the goal is the same – don't grow old; stay young; don't succumb to illness.
Over the last century, these ideas of legend have combined with concepts popular in science fiction to lead to the comprehensive philosophy known as transhumanism. In the 1920s, several seminal written works discussed how advances in science and technology could affect society and the human condition. These essays, along with notable contributions from science fiction authors (like Aldous Huxley's "Brave New World" from 1932) got people thinking about the future of the human race – space colonization, bionic implants, mental implants and more.
In the latter half of the 20th century, these ideas gathered momentum. The cryonics movement (frozen preservation of the body to be revived at a later date – more on this later) began, and the term "transhuman" was coined. Organizations devoted to individual elements of the transhumanist philosophy, such as life extension, cryonics and space colonization, began to bubble up. The 1990s saw the founding of the Extropy Institute, which brought these disparate groups under one umbrella of people with futurist and transhuman ideas. The World Transhumanist Association followed in the institute's footsteps, acting as a coordinating international nonprofit organization for all transhumanist groups. Most recently, Humanity+ developed, pulling together all the leaders of the transhumanist philosophy and helping to spread awareness of their related ideas globally.