Foundationalism - Varieties of Foundationalism

Varieties of Foundationalism

The chief division within foundationalism is between internalist and externalist varieties. Typically, internalist foundationalists hold that basic beliefs are justified by mental events or states, such as experiences, that do not constitute beliefs (these are called non-doxastic mental states). Alternatively, basic beliefs may be justified by some special property of the belief itself, such as its being self-evident or infallible.

Externalist foundationalists hold that belief might be justified by factors that the believer is unaware of, such as the objective likelihood that the belief is true. Types of externalist foundationalism include reliabilism (although not all reliabilists are foundationalists) and Reformed epistemology. Thomas Reid and the Stoics are often considered to be externalist foundationalists, though this attribution remains controversial.

From the early modern period till the late twentieth century, the two dominant varieties of foundationalist theories were rationalism and empiricism (or British empiricism), both of which are internalist views. Strictly speaking, neither empiricism nor rationalism is necessarily committed to foundationalism (it is possible to be an empiricist coherentist, for example, and that was a common epistemological position in 20th century philosophy).

Rationalism is the general name for epistemological theories that maintain that reason is the source and criterion of knowledge. Rationalists generally hold that so-called truths of reason are the (most important) epistemologically basic propositions. The historical, continental rationalism expounded by René Descartes is often regarded as antithetical to empiricism, while some contemporary rationalists assert that reason is strongest when it is supported by or consistent with empirical evidence and hence relies heavily on empirical science in analyzing justifications for belief. Descartes famously held that some of these truths, namely the cogito, are known innately and therefore constitute basic innate knowledge, a view not always held amongst contemporary rationalists.

Empiricism is the general name for epistemological theories that maintain that sensation reports are the source and criterion of knowledge. Classical empiricists generally held that such reports are indubitable and incorrigible and therefore worthy of serving as epistemologically basic propositions.