There is some anxiety with some folk about the idea of "post-modern" thought. I am not sure where this anxiety is rooted and I am not that smart to understand all the nuanced philosophical arguments that people can articulate and understand about different "isms". Recently I came across a bit of a metaphor that helps me understand post-modern a little better which I want to share and keep for later reference.
This metaphor is rooted in the understanding of the "arts" (of which I am not the most informed so hang with me).
My wife shares with me that Classical music has certain rules that composers had to follow. So if you were going to do one thing in the musical composition, then you were required to do something else. Certain harmonies are 'allowed' and others are not. This is in part why, I think, classical music will not have a chord that you hear in jazz music. Speaking of jazz, it operates the same way. If you are working under the rules of jazz, then you have to honor those rules of the art.
In the world of the visual arts, if you were painting in the modern age, then you also had rules that you followed. I am not sure what those rules are (thus my lack of knowledge in the arts), but you might be able to see these "rules" applied to impressionist art. These visual arts, when you were working under these different 'rules', had requirements that you obliged by and honored and everyone followed them.
I get this feeling when I see Pollock's art and think, "that is just paint dumped on a canvas, that is not art. I could do that!" My brain is viewing "art" as that which follows a set of rules (which I may not be able to define), and if it violates those rules then I declare it as "not art".
Post-modernism is that time that is upon us that come to the understanding that respects these different sets of "rules". It seems to suggest that we are now no longer limited in our scope of expression and understanding of the world. We now understand that all of these sets of "rules" that exist all have truth in them and no one set of rules has all the truth. There is no one painting that ends the need to have paintings. As great as Dylan was, even Bob Dylan did not end the need to create more music. He did not have exclusive and exhaustive access to music truth.
We live in a time that respects more sets of "rules" in such a way that we no longer require everyone to play by the same set of "rules" in order to paint, compose music or even create theology.
Post-modernism is the rule that respects all the rules.
(Which is why many post-moderns will argue with you when you do not respect all sets of rules.)