In this podcast we cover the supposed hierarchy of knowledge from "the certainty" of mathematical proof through to the "near certainty" gifted to us by scientific arguments supported by evidence all the way down to the lowly philosophical arguments that are a mere matter of taste. We explore more about the tension between realism and its alternatives, how contributing to science is available to anyone (because the evidence is almost everywhere) and finally we end with an exploration of what Popper had to say on some of these topics.