Epistemic infinitism

If you believe something rationally, you believe it for a reason. And that reason can’t just be any old reason. You’ve got to rationally hold it as a good reason. In order to do so, you must have another reason. And that reason needs another. And so a regress of reasons ensues. This is a rough-and-ready picture of the epistemic regress problem. Epistemic infinitism is the view that justifying reasons are infinite, and so it is a particular solution to the regress problem. Consider, also, that justification comes in degrees – some beliefs are better justified than others. Moreover, it seems that people can know things better than others. Call this the gradability phenomenon. Epistemic infinitism is the view that for someone to be justified maximally is for that person to have an infinite series of supporting reasons.

Epistemic infinitisms admit of a wide variety. Differences between versions of infinitism arise according to two factors for the view: one dialectical, the other ecumenical. The dialectical factor for epistemic infinitisms is the matter of what philosophical problems or questions they answer. Infinitisms are designed to either provide models for how to solve the epistemic regress problem or address the phenomenon of the gradability of justification and knowledge. Infinitisms will differ depending on which issue they are designed to address, and an infinitism designed to address one issue may not be the same as one designed to address another. The ecumenical factor for epistemic infinitisms is the matter of how consistent the view is with other competing theories about how to address the regress problem and the gradability phenomenon. With the regress problem, infinitism’s main competitor theories are foundationalism, the view that there are basic beliefs for which there is no need for further reason, and coherentism, the view that justifying reasons come in large mutually supporting packages. For the most part, infinitism is taken to be a form of noncoherentist antifoundationalism about justification, because the infinitist holds that reasons must be infinitely long chains of nonrepeating reasons. However, there are versions of infinitism consistent with both foundationalism and coherentism. Infinitism faces a variety of challenges, and two of particular importance are whether infinitism is actually a form of scepticism and whether infinitism is a complete theory of justification.