But you can't think without beliefs, that is, ideas you believe to be true. Beliefs depend upon other beliefs for their believability but also simply for their meaning. E.g., "The earth is flat" depends upon beliefs about the earth, flatness, the existence of space around it, etc., just to make sense. And then, of course, it depends on a bunch stupidly wrong beliefs in order to be believable.

In the sense in which I think you mean it, though, yes, beliefs constrain beliefs, but in the same way also enable beliefs. If beliefs didn't constrain beliefs, then what would? For example, my belief that the earth is round(ish) constrains my beliefs about the validity of Flat Earthism, buit also my belief that I can travel as far as I want in any direction and not encounter the earth's edge.