Knowledge: True Belief Fully Guaranteed

Epistemology means an exploration on the nature, resource and restriction of knowledge. The classical definition of knowledge is "justified true belief. This definition includes three elements: justification, true and belief. But the classical definition was challenged by "Gettier's Problems" in 1963. Edmund L. Gettier, an American philosopher raised two counter-examples in 1963, and these examples proved that a justified true belief did not necessarily constitute knowledge. Although the classical definition of knowledge was challenged by "Gettier's Problems", it did not perish, conversely, it kept prosperous during the late part of 20th century.Deep explorations on internalism are made by Anglo-American philosophers after Gettier, meanwhile, some new researches on externalism are provided too. The nucleus viewpoint of internalism is that the criterion of a proposition having justification or not is within the subject's recongnizing power, and the subject can know whether a certain proposition possesses justification or not through this or that means. Intemalism includes deontology, foundationalism and coherenism. Externalism resorts the criterion of knowledge to the external conditions of recognition, and it thinks that if only the producing process of a true belief conforms to the conditions of justification, is the belief knowledge. The style of externalism in 20th century is reliablism. On the basis of strictly analysis, Plantinga points out that all styles of intemalism and extemalism are failed to define knowledge, for "proper function of recognition faculty" -the necessary condition of knowledge- is neglected by all of them.Inheriting the tradition of extemalism, Plantinga looks on proper function of recognition faculty as a critical point of knowledge. He states and argues for his new definition of knowledge comprehensively: knowledge is sufficiently warranted true belief. Plantinga use the term "warrant" to substitute for the term "justification" used in the traditional definition of knowledge. This substitution is for the purpose of emphasizing that it's "warrant" that accurately expresses "positive epistemic status".