The topic of demonstration lies at the intersection of logic and epistemology. It is motivated by the following question: what features must an argument possess to be suitable for providing us with knowledge? A first, obvious thought is that it ought to be valid and to have true premises. But some ancient philosophers came to the view that this is not yet sufficient for an argument to grant knowledge of the truth of its conclusion; there are further requirements, concerning the epistemic status of its premises and the relations they bear towards its conclusion.