"There are no absolute truths" is logical fallacy. While it claims there are no absolute truths, it itself presents itself as an absolute truth, thereby contradicting itself. So much for postmodernism.
For the record, as Epimenides might not tell you, but Godel could, and Whitehead and Russel would so much like to despute, due to this self-refferential fallacy, formal logic is not a closed system. And as such, not a secure one. Therefore, the Post-Modernist tells you that any truth based on this formal system is debatable under the formal system itself
and he's right. So let's just stick with MU.