A proposition laid down as one from which we may begin; an assertion that is taken as fundamental, at least for the purposes of the branch of enquiry in hand. The axiomatic method is that of defining a set of such propositions, and the proof procedures or rules of inference that are permissible, and then deriving the theorems that result. It may be thought to be a hallmark of a particularly rigorous or ‘scientific’ approach to theories to demand that they should be axiomatized; on the other hand a willingness to rethink and challenge even accepted axioms has its own value.