Post-Structuralism: From Point A to Point B

I thought I had a basic understanding of postmodern / post-structuralist theory. Was I wrong?

This week, we looked at Foucault's teachings on what "writes" literary works. Foucault argues that a work is "written" by the mind of the group surrounding it-- it is a "fiction of discourse." He emphasizes the meaning of the author's proper name and concludes that only cultural discourse makes a work literary. Much of this seems foreign to my previous understandings of this movement.

I knew that postmodernism emphasizes the importance of context and the theory that works do not suddenly appear out of nowhere but rather are shaped by their "situatedness" within history. This coincides with Foucault's thoughts about the authorship of culture-- that the people create a work.

However, my previous courses have taught that postmodernism rebells against the modernist mantra, "Make it new," by returning to the past. I did not see this highlighted within Foucault's writings, but perhaps he makes implicit reference to the idea of "return" by acknowledging the importance of context. Related to this concept is the idea that works influence or even create each other. Does Foucault include the texts prized by the author / culture in his definition of culture?

I thought that postmodernism rejected of the scientific in favor of the spiritual or supernatural, but I didn't see this explicitly stated in Foucault, either. If Foucault assumes that the authority culture (which has authored texts) has rejected spirituality in favor of science, and he argues that this authority culture should be questioned in light of power, perhaps he lays a framework for the acceptance of the magical.

Finally, I always equated postmodernism with a rejection of metanarratives, or overarching truths. However, Foucault doesn't seem to make statements about the nonexistence of truth. (If he had, I could have thrown his work out my dorm window, since he would have no authority to tell me how to interpret literature.) Our lecture emphasized that Foucault wasn't concerned with ethics. We assumed that he believed that it didn't matter who authored a work. Does his lack of concern with ethics make him unethical? My heart's response says yes.

Assuming that my previous understandings of post-structuralism were correct, I would like to know how literary theory evolved from the statements of Foucault to the tenents declared in today's university courses.