I do like postmodernism. It was the staple of late twentieth-century intellectualism and thought. I don’t particularly think it was saying anything new. Others have noticed what postmodernism was saying. But it said it differently, and in a more appealing less confrontational way.
When postmodernism says nothing is truly sacred, it means everything operates from the standpoint of its difference to all other things. Sometimes Man stands in contrast to animal. Man with a big ‘M’ may even stand uppercase man. And man often stands against woman. But really there is only these series of differences. Nothing has meaning in itself.
Science, religion, and philosophy are ordinary activities, and not beyond analysis. One can think of the idea of paradigm put forward by Thomas S Kuhn as an example of science. Atheism and agnosticism as examples of religious analysis. And Wittgenstein’s Philosophical Investigations as a meta-philosophical analysis.
For philosophy to be reflexive is important. Any ideas to truth-claims are dangerous and need to be carefully analysed and understood in order not to fall into complacency. One’s own self-righteousness leads to not only metaphorical blindness but generally ends in conflict. The only shared world there is the physical one. Mental ones rely on it, not the other way around.