Extropianism, also referred to as the philosophy of extropy, is an "evolving framework of values and standards for continuously improving the human condition". Extropians believe that advances in science and technology will some day let people live indefinitely. An extropian may wish to contribute to this goal, e.g. by doing research and development or by volunteering to test new technology.

Originated by a set of principles developed by the philosopher Max More, The Principles of Extropy, extropian thinking places strong emphasis on rational thinking and on practical optimism. According to More, these principles "do not specify particular beliefs, technologies, or policies". Extropians share an optimistic view of the future, expecting considerable advances in computational power, life extension, nanotechnology and the like. Many extropians foresee the eventual realization of indefinite lifespans or immortality, and the recovery, thanks to future advances in biomedical technology or mind uploading, of those whose bodies/brains have been preserved by means of cryonics.