Knowledge that can be said to exist in forms or propositions is sometimes referred to as ‘knowledge-that.’ Propositional knowledge includes the knowledge of certain facts that can be expressed in sentences of a declarative form and so be either true or false. For instance, the statement that Paris is the capital of France is an example of propositional knowledge. It is different from procedural knowledge, for instance knowledge that is associated with being able to perform particular activities, such skills as riding a bicycle or performing with an instrument.
Plato, Gettier and indeed other philosophers have spent time studying the nature of propositional knowledge, as well as the notions of justification for it, as well as its truth and belief. Elaborating on the distinction, a distinctive feature of propositional knowledge is that of being justified; in this regard, if one is to hold that a certain proposition is true, one ought to provide sufficient reasons for such enrollment. This has brought about many issues in the field of epistemology in particular what can be considered enough justification or indeed ontological questions about the nature of truth.
