It's the job of intellectuals and writers to cast doubt on perfection.
Doubts are like stains on a shirt. I like shirts with stains, because when I'm given a shirt that's too clean, one that's completely white, I immediately start having doubts.
It's very useful when politicians have doubts because there are so many choices to be made in the world.
I don't have any doubts either about the Universal Declaration of Human Rights. Perhaps some more should be added to the list, but I don't have the slightest doubt about human rights.
People with lots of doubts sometimes find life more oppressive and exhausting than others, but they're more energetic - they aren't robots.