1. Jean Baudrillard is a postmodern critic noted mostly for his stance that culture has overtaken nature. We tend to consider that something exists in the world and then we come up with a word for that thing. Baudrillard says that this used to be the case, but now signs (words) have taken priority. He thinks that natural desires have been obscured by counterfeit desires and this has been done most visibly by advertising and the media who tell us what we want. Thus, our natural desires are obscured by these signs of advertising, media and consumerism. He calls this proliferation of sign dominance simulacrum, which means a sign (or word) that is a representation but carries a notion of a sham or counterfeit.
2. Donna Haraway is most known for her text "A Manifesto for Cyborgs." Many postmodern theorists try to understand identity as a confluence of different cultures, disciplines, practices, and belief systems. Such theorists understand that identity is a collage, not something essential and certainly not stereotypical. Ignoring the traditional romanticized notions of a pure, rustic or even primitive identity, Haraway offers the cyborg as something literally on a boundary between human and machine. Living on a boundary, as postgender or even posthuman is a way to at least consider a perspective (cyborg) from which one is not in the position of dominance nor subjugation.
3. bell hooks' (her name is presented as such to honor her great-grandmother) work deals with identity, particularly African-American identity and argues against any essential African-American identity or experience. She argues that such an essentialism is akin to stereotyping and limits the conceptions of what African-Americans can identify with and "be." She argues that postmodern theorizing has been guided too much by white male theorists steeped in jargon and thus, limited to elite academics. She thinks such theorizing is exclusionary and notes that this is contrary to some of the repeated traits of postmodern thought such as difference, liberation and multiplicity. Thus, she theorizes about a diverse range of identities, not one essential, and this is important since part of the postmodern project is to deconstruct identity. This is a difficult task, she notes, because subjugated people have been struggling to assume an identity, a practice which is now more free but also more interconnected with other aspects of culture.
4. Gilles Deleuze and Felix Guattari were collaborators and this is why I couple the two here. Their theories were very much about anti-hierarchical notions. For instance, they replaced the "tree of knowledge" symbol with a rhizome because a rhizome has no central structure. The rhizome is not anchored by any origin or root system. Its growth is always "becoming," and thus not fixed to any essential idea or body of knowledge.
5. In Jean-Francois Lyotard's work "The Postmodern Condition," he says that postmodernism "rages against metanarratives." This means that the postmodern theorist does not believe that any universal truth or any one system of thought is more progressive or more civilized than another. For example, Lyotard argues that metanarratives such as the Enlightenment or the promise of a better future based on technological progress are no longer credible. Instead he argues for diversity and plurality.