Epistemic internalism is the view that the reliability of a belief is determined by its internal properties, such as its coherence or its logical consistency.

Epistemic externalism is the view that the reliability of a belief is determined by its external properties, such as its causal origins or its relationship to the world.

The coherence argument for epistemic internalism argues that the reliability of a belief is determined by its coherence or its logical consistency with other beliefs.

The causal argument for epistemic externalism argues that the reliability of a belief is determined by its causal origins, such as its being caused by a reliable process.

The Gettier objection to epistemic internalism argues that there are cases in which a belief can be justified by its internal properties but still be false.

The skeptical objection to epistemic externalism argues that there is no way to know for sure that our beliefs are caused by reliable processes.

The defeasibility theory is a response to the Gettier objection that argues that justified beliefs can be defeated by new evidence.

The reliabilist theory is a response to the skeptical objection that argues that justified beliefs are those that are formed by reliable processes.

Many philosophers believe that epistemic internalism and externalism are compatible, meaning that it is possible to hold both views at the same time.

René Descartes is most closely associated with epistemic internalism, as he argued that the only beliefs that can be known for certain are those that are self-evident.

John Locke is most closely associated with epistemic externalism, as he argued that the reliability of a belief is determined by its causal origins.

A common criticism of epistemic internalism is that it is too narrow, as it excludes beliefs that are justified by external factors, such as reliable processes.

A common criticism of epistemic externalism is that it is too broad, as it allows for beliefs that are justified by unreliable processes.

The contextualist theory is a response to the criticism that epistemic internalism is too narrow, as it argues that the reliability of a belief can depend on the context in which it is held.

The reliabilist theory is a response to the criticism that epistemic externalism is too broad, as it argues that justified beliefs are those that are formed by reliable processes.