If you had a prior that the probability that life was ubiquitous in the universe is ten to minus a hundred, then finding life on europa is not going to change that by that much. But i can't blame just basian reasoning on that, or give credit to basian reasoning. I have to tell you what my priors are to draw that conclusion. John shoning also asks a basian question: Is it possible to place choosing a prior with another basian sub problem, pushing the choice of prior further up the stack until you reach a point closer to the edge of the system? A, i mean, roughly, i i think no is the right answer. You can sort