The critical perspective that the age of humanism has come to an end. It is premised on the idea that humanism's twin assumptions that humans are both knowable and reasonable is false. It rejects the idea that humans can be known, largely on the grounds that the dividing line between human and non-human or animal is difficult to delineate in the first place and highly permeable too. Donna Haraway's work on cyborgs is especially important in this regard. It also rejects the idea that because humans have reason (or at least bestow upon themselves the idea that they have reason), this is sufficient to make them the only arbiters of the fate of the planet and all its other non-human inhabitants. Posthumanism is a highly eco-conscious discourse.
C. Wolfe What is Posthumanism? (2010).
Subjects: Literary Theory and Cultural Studies.