No ideology / philosophy / religion ever provides a complete worldview. So there will always be as many worldviews as there are people, and the world will always be "pluralistic" in that respect.

But any group of people can only collaborate successfully insofar as their worldviews align - or insofar as their differences don't matter. For instance, a vastly different taste in movies shouldn't cause a problem for two nurses working in the same unit at a hospital. But it would cause a big problem for two people trying to co-direct a film.

That latter scenario is analogous to our current situation with the American government. We have a lot of vastly different opinions on how it should be run, and we need to find a way to get on the same page. We don't need to get on exactly the same line on the same page, but we need to get onto the same page to the extent that our differences don't matter.

Although it may not always seem like it, we actually have a pretty big head start in this regard, since we are all human after all. We all can agree that food, water, clean air, and shelter, are necessary for our survival and happiness. And we can all probably agree that we generally don't want to feel pain, and we do want to feel happy.

But we need to agree on a few more things in order to have a functioning society together. I think a good start is simply to agree that undemocratic evidence (i.e. the words of prophets or holy books claiming to be the one source of truth) is unacceptable.

And another thing I think we should - and should be able to - agree on is that the only evil in the world is pain itself, and that the only goodness in the world is happiness, pleasure, and the absence of pain. A lot of people like to think other concepts like justice are goods in themselves, but they are wrong. Justice is at best merely a system or heuristic for facilitating happiness. And it's detrimental to put it on a pedistal , and prioritize it above happiness itself. Similarly, most religions, like Christianity, believe that good and evil derive from adherence to laws written in the Bible, rather than merely from pain and happiness themselves. And they are wrong too.

So there you have it: A way to decide what's true (i.e. claims supported by democratic evidence), and a way to decide what's valuable (i.e. whether it causes pain or happiness).

I think if we can get everybody to agree on those two things, will be in a much better place for making group decisions together. And the best part is, I think both those things are so reasonable that it's actually feasible that we can get everyone to agree on those two things.