A transhuman is a life form with an intelligence comparable or superior to that of humans.
It thus has the following characteristics:
- a life form:
- it is an organised system
- it has a limit; it is possible to say what is in the system, and what is not
- it exchanges energy and substances with its environment
- it can reproduce itself
- it has a memory
- it communicates information via a language
A posthuman or post-human is a hypothetical future being whose capabilities so radically exceed those of present humans as to be no longer human by current standards. A posthuman can also be described as the creature that results from radical human enhancement. In these ways, the difference between the posthuman and other hypothetical sophisticated non-humans is that a posthuman was once a human, either in its life time or in the life times of some or all of its direct ancestors. As such, a prerequisite for a posthuman is a transhuman, the point at which the human being begins surpassing his own limitations, but is still recognisable as a human person.
Posthumans could be a symbiosis of human and artificial intelligence, or uploaded consciousnesses, or the result of making many smaller but cumulatively profound technological augmentations to a biological human, i.e. a cyborg. Some examples of the latter are redesigning the human organism using advanced nanotechnology or radical enhancement using some combination of technologies such as genetic engineering, psychopharmacology, life extension therapies, neural interfaces, advanced information management tools, memory enhancing drugs, wearable or implanted computers, and cognitive techniques.
The term can also refer to the possibility of a technological singularity or that humanity or a segment of humanity will create or evolve into a "posthuman God".
Homo excelsior (Latin for "higher man") is an alternate term used in the literature of transhumanism for the posthuman. The use of the Latin binomial implies the transhumanist idea of participant evolution as a hypothetical human progression through an intermediary form of the transhuman to a new species distinct from Homo sapiens.
As used here, "posthuman" does not refer to a conjectured future where humans are extinct or otherwise absent from the Earth. As with other species who diverge from one another, both humans and posthumans could continue to exist.
"Posthuman" should not be confused with "posthumanism," which is a European philosophical extension of humanism.