Some of that may be true, but to affect the world, you nonetheless need to do things. And to do those things, you need to take something for granted, assume som

Some of that may be true, but to affect the world, you nonetheless need to do things. And to do those things, you need to take something for granted, assume something, to complete the task. That set of things you're willing to take for granted is actually your relevant set of beliefs, because they inform your actions. That's where the important decisions are made, and this is the constant crisis of trying to figure out the right solution with nowhere near enough information. We can all, in theory, believe that we're wrong about most things, and this is most likely true. But, ultimately, there are things one is willing to do even if they could be wrong about them, because not doing anything is often worse. Sitting in constant doubt is effectively deciding not to participate.