Foundationalism

Foundationalism acknowledges a two-tier structure in justification: Some justification is noninferential (that is, foundational), and all other justification is inferential (that is, nonfoundational) in that it derives ultimately from foundational justification. This view was proposed by Aristotle (384–322 B.C.E.), in Posterior Analytics, as a view about knowledge. It emerges too in René Descartes's Meditationes de prima philosophia (1641; Meditations on first philosophy), where it joins with the assumption that foundations of knowledge must be certain. Foundationalism is represented in varying forms in the writings of John Locke (1632–1704), Kant, Bertrand Russell (1872–1970), Clarence Irving Lewis (1883–1964), and Roderick M. Chisholm (1916–1999), among others. Foundationalism about evidence and justification explains a belief's (or a proposition's) having justification for a person; it does not explain one's showing that a belief has justification or is true.

Versions of foundationalism vary in explaining noninferential (foundational) justification, and in explaining how justification transmits from foundational beliefs to nonfoundational beliefs. Some philosophers have assumed that foundational beliefs must be certain (that is, indubitable or infallible). This leads to radical foundationalism, which requires that foundational beliefs be certain and that such beliefs guarantee the certainty or the truth of supported nonfoundational beliefs. Radical foundationalism faces two problems. First, very few (if any) empirical beliefs are certain. Second, beliefs that might be candidates for certainty (for instance, the belief that I am thinking) are not informative enough to guarantee the certainty or the truth of specific inferential beliefs about the external world (for example, beliefs of the sciences).

Modest foundationalism states that foundational beliefs need not possess or yield certainty and need not guarantee the truth of justified nonfoundational beliefs. A noninferentially justified, foundational belief has justification that does not derive from other beliefs, even if the causal basis of foundational beliefs includes other beliefs. Modest foundationalists have offered three influential approaches to noninferential (foundational) justification: (1) self-justification, (2) justification by nonbelief, nonpropositional experiences, and (3) justification by a reliable nonbelief origin of a belief.

Recent proponents of self-justification include Chisholm and C. J. Ducasse (1881–1969). They held that a foundational belief can justify itself, apart from evidential support from something else. Proponents of foundational justification by nonbelief experiences dissent. They hold, following Lewis, that foundational perceptual beliefs can be justified by nonbelief sensory or perceptual experiences (for example, my nonbelief experience involving seeming to see snow falling here) that either make true, are best explained by, or otherwise support those foundational beliefs (for example, the belief that snow is falling here). Advocates of foundational justification by reliable origins hold that noninferential justification depends on nonbelief belief-forming processes (such as perception, memory, and introspection) that are truth conducive, that is, they tend to produce true rather than false beliefs. Such reliabilism invokes as a justifier the reliability of a belief's nonbelief origin, whereas the previous view invokes the particular sensory experiences underlying a foundational belief. Proponents of modest foundationalism typically agree that noninferential justification for a belief can be defeated upon the acquisition of new justified beliefs, at least in most cases.