Internalism and externalism in epistemology

The internalism/externalism debate in epistemology is primarily concerned with the conditions or factors by virtue of which beliefs acquire the status of being epistemically justified. Internalism holds that these justification-conferring factors must all be ‘internal’ to the subject’s perspective on the world. However, depending on how the notion of internal is understood, internalism ap-pears in different forms. Access internalism, the most common form of internalism, holds that the justification-conferring factors must be reflectively accessible to the subject, such that he is able to find, with regard to the beliefs he holds, whether they are justified. Internalism captures the pre-theoretic intuition that having justification for a belief is a matter of having good reasons for that belief. It also treats the problem of scepticism seriously and explains why it has its source in internalism. Internalism has, however, faced two important objections: (1) it has been objected that internalism fails to deliver a genuinely truth-conducive conception of justification; and (2) that no available account of the access requirement could provide it with a viable basis to realize its aspirations.

In an externalist account of justification, some justification-conferring factors of a belief are per-mitted to fall outside the subject’s ken and beyond the reach of the subject’s reflective access. Externalism can plausibly explain why justified beliefs are likely to be true; but by losing sight of the subject’s perspective, externalism fails to appreciate the force of the sceptical challenge. Ex-ternalists have had a hard time explaining the widely shared intuition that beliefs formed in de-mon world scenarios enjoy as much justification as they do when formed in (phenomenologically identical) normal circumstances. In the face of such challenges, both the internalist and external-ist accounts have made significant compromises, in view of which a pluralistic approach to the question of epistemic justification has become a live option.