This article provides an introduction to transhumanism and posthumanism, two philosophies that inform postdigital scholarship. While all postdigital humans are entangled in human-machine assemblages, for transhumanism, these new forms of being signal a trajectory of progress towards a radically enhanced human or even a superior successor species. Posthumanists, meanwhile, view these assemblages as disruptive of the concept of the ‘human’ that has been central to post-Enlightenment Western philosophy. This opens up possibilities of thinking beyond human-centric, exploitative, and destructive lifeways, and the dream of extending the self into perpetuity through technology.