They didn't think anything could be objectively true. I can understand their point of view. It has strong support, particularly in the academic community. But some statements really are true. Some things really exist.
Some actions really are just.
Some creations really are beautiful. And some things really are better than others. Here are some examples. Michelangelo Buonarotti is a better sculptor than I am. Pierre Auguste Renoir is a better painter than I am.