What it means to be human is inherently incomplete or in a state of permanent mutability. This is excellent for it opens the way to the questions of the inhuman, posthuman, and nonhuman to take center stage in the analysis of what it means to be a subject, which is a core question for education. The question of the inhuman at the core of the human is brought into focus in the work of the Slovenian School of Psychoanalysis, whose central Lacanian tenet refers to ontological negativity as irreducible. Reality is incomplete and contradictory entangled with the Real as its irreducible other. Timothy Morton's work on the non-human argues that theorizing solidarity with the non-human living world is possible, indeed inevitable, through thinking an ecological symbiosis of human and nonhuman, which necessarily disrupts our notions of Nature and our place in it at a fundamental level. Finally, the recent developments in the neurosciences, robotics, biogenetics and AI create the conditions ripe for speculation regarding the future of humans in radical ways. It will be argued that Malabou's notion of plasticity can address the questions pertaining to the non-human, posthuman, and the inhuman in essential ways.