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.
Agrippa the SkepticAgrippa (Ἀγρίππας) was a Pyrrhonist philosopher who probably lived towards the end of the 1st century CE. He is regarded as the author of "The Five Tropes (or Modes, in τρόποι) of Agrippa", which are purported to establish the necessity of suspending judgment (epoché). Agrippa's arguments form the basis of the Agrippan trilemma. Sextus Empiricus described these "modes" or "tropes" in Outlines of Pyrrhonism, attributing them "to the more recent skeptics"; Diogenes Laërtius attributes them to Agrippa.
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.
FoundationalismFoundationalism concerns philosophical theories of knowledge resting upon non-inferential justified belief, or some secure foundation of certainty such as a conclusion inferred from a basis of sound premises. The main rival of the foundationalist theory of justification is the coherence theory of justification, whereby a body of knowledge, not requiring a secure foundation, can be established by the interlocking strength of its components, like a puzzle solved without prior certainty that each small region was solved correctly.
Philosophical skepticismPhilosophical skepticism (UK spelling: scepticism; from Greek σκέψις skepsis, "inquiry") is a family of philosophical views that question the possibility of knowledge. It differs from other forms of skepticism in that it even rejects very plausible knowledge claims that belong to basic common sense. Philosophical skeptics are often classified into two general categories: Those who deny all possibility of knowledge, and those who advocate for the suspension of judgment due to the inadequacy of evidence.
CoherentismIn philosophical epistemology, there are two types of coherentism: the coherence theory of truth; and the coherence theory of justification (also known as epistemic coherentism). Coherent truth is divided between an anthropological approach, which applies only to localized networks ('true within a given sample of a population, given our understanding of the population'), and an approach that is judged on the basis of universals, such as categorical sets.
RelativismRelativism is a family of philosophical views which deny claims to objectivity within a particular domain and assert that valuations in that domain are relative to the perspective of an observer or the context in which they are assessed. There are many different forms of relativism, with a great deal of variation in scope and differing degrees of controversy among them. Moral relativism encompasses the differences in moral judgments among people and cultures.
