Why do we bother with the formality of skepticism and the scientific method? These ideas seem so familiar as to represent basis of how we normally think, but this falls into yet another one of those cognitive illusions that we are so prone. There are vast holes in our knowledge that come from what we believe, rather than what we know. In order to build reliable systems of knowledge, from which we can create practical applications, we have to apply a formalized system of checking and rechecking what we feel is true. Thus, Critical Reasoning relies on skepticism and the scientific method. It means that we can only verify things that can be disproven and only accept knowledge that is proven repeatedly. This episode looks at some differences between knowledge and belief.