Relationalism vs. Bayesianism

We compare and contrast the basic principles of two philosophies: Bayesianism and relationalism. These two philosophies are both based upon criteria of rationality. The analogy invoked in such a comparison seems rather apt when discussing tentative proofs of quantum nonlocality. We argue that Bayesianism is almost to quantum theory, what general covariance is to general relativity. This is because the Bayesian interpretation of quantum theory can be given a relational flavour.