Epistemology is the branch of philosophy concerned with knowledge. Epistemologists study the nature, origin, and scope of knowledge, epistemic justification, the rationality of belief, and various related issues. Debates in (contemporary) epistemology are generally clustered around four core areas:
- The philosophical analysis of the nature of knowledge and the conditions required for a belief to constitute knowledge, such as truth and justification
- Potential sources of knowledge and justified belief, such as perception, reason, memory, and testimony
- The structure of a body of knowledge or justified belief, including whether all justified beliefs must be derived from justified foundational beliefs or whether justification requires only a coherent set of beliefs
- Philosophical skepticism, which questions the possibility of knowledge, and related problems, such as whether skepticism poses a threat to our ordinary knowledge claims and whether it is possible to refute skeptical arguments
Reliabilism, a category of theories in the philosophical discipline of epistemology, has been advanced as a theory both of justification and of knowledge. Process reliabilism has been used as an argument against philosophical skepticism, such as the brain in a vat thought experiment. Process reliabilism is a form of epistemic externalism.
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. Epistemologists are concerned with various epistemic features of belief, which include the ideas of warrant, knowledge, rationality, and probability, among others.
Edmund Lee Gettier III was an American philosopher at the University of Massachusetts Amherst. He is best known for his article written in 1963: "Is Justified True Belief Knowledge?", which has generated an extensive philosophical literature trying to respond to what became known as the Gettier problem.
Knowledge is a form of awareness or familiarity. It is often understood as awareness of facts or as practical skills, and may also mean familiarity with objects or situations. Knowledge of facts, also called propositional knowledge, is often defined as true belief that is distinct from opinion or guesswork by virtue of justification. While there is wide agreement among philosophers that propositional knowledge is a form of true belief, many controversies in philosophy focus on justification. This includes questions like whether justification is needed at all, how to understand it, and whether something else besides it is needed. These controversies intensified due to a series of thought experiments by Edmund Gettier and have provoked various alternative definitions. Some of them deny that justification is necessary and suggest alternative criteria. Others accept that justification is an essential aspect and formulate additional requirements.
The Gettier problem, in the field of epistemology, is a landmark philosophical problem concerning the understanding of descriptive knowledge. Attributed to American philosopher Edmund Gettier, Gettier-type counterexamples challenge the long-held justified true belief (JTB) account of knowledge. The JTB account holds that knowledge is equivalent to justified true belief; if all three conditions are met of a given claim, then we have knowledge of that claim. In his 1963 three-page paper titled "Is Justified True Belief Knowledge?", Gettier attempts to illustrate by means of two counterexamples that there are cases where individuals can have a justified, true belief regarding a claim but still fail to know it because the reasons for the belief, while justified, turn out to be false. Thus, Gettier claims to have shown that the JTB account is inadequate because it does not account for all of the necessary and sufficient conditions for knowledge.
In philosophical epistemology, there are two types of coherentism: the coherence theory of truth; and the coherence theory of justification.
Contextualism, also known as epistemic contextualism, is a family of views in philosophy which emphasize the context in which an action, utterance, or expression occurs. Proponents of contextualism argue that, in some important respect, the action, utterance, or expression can only be understood relative to that context. Contextualist views hold that philosophically controversial concepts, such as "meaning P", "knowing that P", "having a reason to A", and possibly even "being true" or "being right" only have meaning relative to a specified context. Other philosophers contend that context-dependence leads to complete relativism.
Linda Trinkaus Zagzebski is an American philosopher. She is the Emerita George Lynn Cross Research Professor, as well as Emerita Kingfisher College Chair of the Philosophy of Religion and Ethics, at the University of Oklahoma. She writes in the areas of epistemology, philosophy of religion, and virtue theory.
Virtue epistemology is a current philosophical approach to epistemology that stresses the importance of intellectual and specifically epistemic virtues. Virtue epistemology evaluates knowledge according to the properties of the persons who hold beliefs in addition to or instead of the properties of the propositions and beliefs. Some advocates of virtue epistemology also adhere to theories of virtue ethics, while others see only loose analogy between virtue in ethics and virtue in epistemology.
Naturalized epistemology is a collection of philosophic views concerned with the theory of knowledge that emphasize the role of natural scientific methods. This shared emphasis on scientific methods of studying knowledge shifts focus to the empirical processes of knowledge acquisition and away from many traditional philosophical questions. There are noteworthy distinctions within naturalized epistemology. Replacement naturalism maintains that traditional epistemology should be abandoned and replaced with the methodologies of the natural sciences. The general thesis of cooperative naturalism is that traditional epistemology can benefit in its inquiry by using the knowledge we have gained from the cognitive sciences. Substantive naturalism focuses on an asserted equality of facts of knowledge and natural facts.
Crispin Gallagher Sartwell is an American academic, philosopher, and journalist who is a faculty member of the philosophy department at Dickinson College in Carlisle, Pennsylvania. He has taught philosophy, communication, and political science at a number of schools, including Vanderbilt University, University of Alabama, Millersville University of Pennsylvania, the Maryland Institute College of Art, and Dickinson College.
Alvin Ira Goldman is an American philosopher who is Emeritus Board of Governors Professor of Philosophy and Cognitive Science at Rutgers University in New Jersey and a leading figure in epistemology.
An infinite regress is an infinite series of entities governed by a recursive principle that determines how each entity in the series depends on or is produced by its predecessor. In the epistemic regress, for example, a belief is justified because it is based on another belief that is justified. But this other belief is itself in need of one more justified belief for itself to be justified and so on. An infinite regress argument is an argument against a theory based on the fact that this theory leads to an infinite regress. For such an argument to be successful, it has to demonstrate not just that the theory in question entails an infinite regress but also that this regress is vicious. There are different ways in which a regress can be vicious. The most serious form of viciousness involves a contradiction in the form of metaphysical impossibility. Other forms occur when the infinite regress is responsible for the theory in question being implausible or for its failure to solve the problem it was formulated to solve. Traditionally, it was often assumed without much argument that each infinite regress is vicious but this assumption has been put into question in contemporary philosophy. While some philosophers have explicitly defended theories with infinite regresses, the more common strategy has been to reformulate the theory in question in a way that avoids the regress. One such strategy is foundationalism, which posits that there is a first element in the series from which all the other elements arise but which is not itself explained this way. Another way is coherentism, which is based on a holistic explanation that usually sees the entities in question not as a linear series but as an interconnected network. Infinite regress arguments have been made in various areas of philosophy. Famous examples include the cosmological argument, Bradley's regress and regress arguments in epistemology.
Infinitism 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.
Epistemic closure is a property of some belief systems. It is the principle that if a subject knows , and knows that entails , then can thereby come to know . Most epistemological theories involve a closure principle and many skeptical arguments assume a closure principle.
Epistemology or theory of knowledge is the branch of philosophy concerned with the nature and scope (limitations) of knowledge. It addresses the questions "What is knowledge?", "How is knowledge acquired?", "What do people know?", "How do we know what we know?", and "Why do we know what we know?". Much of the debate in this field has focused on analyzing the nature of knowledge and how it relates to similar notions such as truth, belief, and justification. It also deals with the means of production of knowledge, as well as skepticism about different knowledge claims.
Formative epistemology is a collection of philosophic views concerned with the theory of knowledge that emphasize the role of natural scientific methods. According to formative epistemology, knowledge is gained through the imputation of thoughts from one human being to another in the societal setting. Humans are born without intrinsic knowledge and through their evolutionary and developmental processes gain knowledge from other human beings. Thus, according to formative epistemology, all knowledge is completely subjective and truth does not exist.
Definitions of knowledge try to determine the essential features of knowledge. Closely related terms are conception of knowledge, theory of knowledge, and analysis of knowledge. Some general features of knowledge are widely accepted among philosophers, for example, that it constitutes a cognitive success or an epistemic contact with reality and that propositional knowledge involves true belief. Most definitions of knowledge in analytic philosophy focus on propositional knowledge or knowledge-that, as in knowing that Dave is at home, in contrast to knowledge-how (know-how) expressing practical competence. However, despite the intense study of knowledge in epistemology, the disagreements about its precise nature are still both numerous and deep. Some of those disagreements arise from the fact that different theorists have different goals in mind: some try to provide a practically useful definition by delineating its most salient feature or features, while others aim at a theoretically precise definition of its necessary and sufficient conditions. Further disputes are caused by methodological differences: some theorists start from abstract and general intuitions or hypotheses, others from concrete and specific cases, and still others from linguistic usage. Additional disagreements arise concerning the standards of knowledge: whether knowledge is something rare that demands very high standards, like infallibility, or whether it is something common that requires only the possession of some evidence.
