Foundationalism

Foundationalism holds that justified beliefs come in two kinds — basic beliefs that are justified directly, not by other beliefs, and non-basic beliefs that derive their justification by inference from the basic ones — so that the structure of knowledge resembles a building resting on secure foundations.

Definition

Foundationalism is the theory that epistemic justification has a two-tier structure in which a set of basic beliefs is justified independently of support from other beliefs, and all other justified beliefs ultimately derive their justification, by inference, from those basic beliefs.

Scope

This topic covers the foundationalist response to the regress of justification, including the notion of basic or non-inferentially justified beliefs, the candidate sources of basic justification such as sense experience and rational intuition, and the spectrum from strong Cartesian foundationalism (basic beliefs are infallible or indubitable) to modest foundationalism (basic beliefs are merely prima facie justified and defeasible). Coherentist and infinitist alternatives are treated as contrasts but developed in their own topics.

Core questions

• Which beliefs, if any, are basic — justified without depending on other beliefs?
• What confers justification on basic beliefs if not other beliefs?
• Must basic beliefs be infallible, or can they be fallible and defeasible?
• How does justification transmit from basic beliefs to the rest of what we believe?

Key theories

Classical (Cartesian) foundationalism

Basic beliefs must be infallible, indubitable, or incorrigible — paradigmatically beliefs about one's own current mental states — and the rest of knowledge is rebuilt by deduction from this certain base, as in Descartes's reconstruction after methodic doubt.

Modest (moderate) foundationalism

Basic beliefs need not be certain; perceptual and introspective beliefs can be non-inferentially yet only defeasibly justified, providing prima facie support that further evidence can override.

History

Foundationalism is the dominant structure in early modern epistemology, given its sharpest form by Descartes, who sought an indubitable foundation in the cogito and rebuilt knowledge from it. Twentieth-century empiricists located the foundation in sense-data or observation, but the difficulty of deriving the external world from such a base, together with Sellars's critique of the given, drove many philosophers toward modest foundationalism or coherentism.

Debates

Whether there are genuinely basic beliefs

Foundationalists hold that the regress of justification must terminate in non-inferentially justified beliefs, while critics, drawing on the problem of the given, argue that a belief cannot be justified by experience alone without further beliefs, threatening to collapse foundationalism into coherentism.

Key figures

• René Descartes
• Roderick Chisholm
• Laurence BonJour
• Ernest Sosa

Seminal works

• descartes-meditations
• sosa1980

Frequently asked questions

What is a basic belief?

A basic belief is one that is justified but not by inference from any other belief; its justification comes from a source such as sense experience, introspection, or rational insight. Non-basic beliefs are then justified by their inferential connections to basic ones.

How does foundationalism answer the regress problem?

It stops the regress of reasons by positing a terminus: basic beliefs that are justified non-inferentially. Because their justification does not require support from further beliefs, the chain of justification need neither continue forever nor circle back on itself.