Evidentialism - The Infinite Regress Argument

The Infinite Regress Argument

Evidentialism also faces a challenge from the infinite regress argument. This argument begins with the observation that, normally, one's supporting evidence for a belief consists of other beliefs. But it seems that these other beliefs can do the job of justifying only if they themselves are already justified. And evidentialism demands that these supporting beliefs be justified by still further evidence if they are to be justified themselves. But this same reasoning would apply to the new, deeper level of supporting beliefs: they can only justify if they're themselves justified, and evidentialism therefore demands an even deeper level of supporting belief. And so on. According to this argument, a justified belief requires an endless supply of reasons. Most philosophers agree that this is an absurd conclusion.

In general, responses to this argument can be classified in the following ways:

• Foundationalism: There exist beliefs that are justified, but not because they are based on any other beliefs. These are called properly basic beliefs, and they are the foundation upon which all other justified beliefs ultimately rest.
• Coherentism: Justified beliefs are all evidentially supported by other beliefs, but an infinite set of beliefs is not generated, because the chains of evidential support among beliefs is allowed to move in a circle. On the resulting picture, a person's belief is justified when it fits together with the person's other beliefs in a coherent way in which the person's various beliefs mutually support one another.
• Conditional Theory of Justification: A belief is justified by a set of beliefs. However this justification operates conditionally, as it depends on the truth of the justifying beliefs. There is not a need for basic beliefs, but one should note that this type of justification is weaker.
• Skepticism: There cannot be any justified beliefs.

Aside from these responses, some philosophers have said that evidential chains terminate in beliefs that are not justified. Others have said that, indeed, there can exist infinite chains of reasons.

Of the main responses, coherentism and skepticism are clearly consistent with evidentialism. Coherentism allows evidential support for all of our justified beliefs in the face of the regress argument by allowing for circular chains of evidential support among beliefs. And the skeptic here is utilizing an evidentialist demand to arrive at her skeptical conclusion.

But because the resulting skepticism is so sweeping and devastating, and because so many reject the legitimacy of the circular reasoning embraced by the coherentist, foundationalism is the favored response of many philosophers to the regress argument. And foundationalism does not so clearly fit together with evidentialism. At first glance, at least, the "basic" beliefs of the foundationalist would appear to be counterexamples to the evidentialist's thesis, in that they are justified beliefs that are not rational because they are not supported by deeper evidence.