This chapter offers a comparison between Mutants (associated with transhumanism) and Cyborgs (posthumanism). Both figures are analysed in respect with the concept of “organology”—the general theory of instruments, for which tools are just external organs, and organs internal tools. In this tradition, mutants and cyborgs embody two ways to achieve human enhancement: mutants as spontaneously generated new functions and cyborgs as the product of conscious and intentional design. Mutants and cyborgs also offer a re-reading of the human body, past, present, and future. Cyborgs show that our organism is susceptible to being complemented by technical devices, such as a mechanical heart. Mutants show that our natural organs are organic machines performing various functions. Both cyborgs and mutants imply that “natural” and “artificial” organs have been designed by various instances (divine or human engineers, or natural selection) and that they might be improved. The natural world is a technological world just as the technological world is a natural one.