InfinitismInfinitism is the view that knowledge may be justified by an infinite chain of reasons. It belongs to epistemology, the branch of philosophy that considers the possibility, nature, and means of knowledge. Since Gettier, "knowledge" is no longer widely accepted as meaning "justified true belief" only. However, some epistemologists still consider knowledge to have a justification condition. Traditional theories of justification (foundationalism and coherentism) and indeed some philosophers consider an infinite regress not to be a valid justification.
FoundherentismIn epistemology, foundherentism is a theory of justification that combines elements from the two rival theories addressing infinite regress, foundationalism prone to arbitrariness, and coherentism prone to circularity (problems raised by the Münchhausen trilemma). Foundherentism was developed and defended by Susan Haack in Evidence and Inquiry: Towards Reconstruction in Epistemology (1993).
FallibilismOriginally, fallibilism (from Medieval Latin: fallibilis, "liable to err") is the philosophical principle that propositions can be accepted even though they cannot be conclusively proven or justified, or that neither knowledge nor belief is certain. The term was coined in the late nineteenth century by the American philosopher Charles Sanders Peirce, as a response to foundationalism. Theorists, following Austrian-British philosopher Karl Popper, may also refer to fallibilism as the notion that knowledge might turn out to be false.
Regress argumentIn epistemology, the regress argument is the argument that any proposition requires a justification. However, any justification itself requires support. This means that any proposition whatsoever can be endlessly (infinitely) questioned, resulting in infinite regress. It is a problem in epistemology and in any general situation where a statement has to be justified. The argument is also known as diallelus (Latin) or diallelon, from Greek di' allelon "through or by means of one another" and as the epistemic regress problem.
Justification (epistemology)Justification (also called epistemic justification) is the property of belief that qualifies it as knowledge rather than mere opinion. Epistemology is the study of reasons that someone holds a rationally admissible belief (although the term is also sometimes applied to other propositional attitudes such as doubt). Epistemologists are concerned with various epistemic features of belief, which include the ideas of warrant (a proper justification for holding a belief), knowledge, rationality, and probability, among others.