Agrippan Problems

In this article I consider Sextus’ account of the Five Modes and of the Two Modes in his Outlines of Pyrrhonism. I suggest that from these we can derive the basic form of a number of different problems which I refer to as “Agrippan problems,” where this category includes both the epistemic regress problem and the problem of the criterion. Finally, I suggest that there is a distinctive Agrippan problem present at the beginning of Hegel’s Science of Logic.

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.

Knowledge and justification, coherence theory of

Coherence theories of justification represent one main alternative to foundationalist theories of justification. If, as has usually been thought, possessing epistemic justification is one necessary condition (along with truth and perhaps others) for a belief to constitute knowledge, then a coherence theory of justification would also provide the basis for a coherence theory of knowledge. While some proponents of coherence theories have restricted the scope of the theory to empirical justification, others have applied it to all varieties of epistemic justification. (There are also coherence theories of meaning and of truth, as well as coherence theories of ethical or moral justification.) The initial contrast between coherence theories and foundationalist theories arises in the context of the epistemic regress problem. It is obvious that the justification of some beliefs derives from their inferential relations to other, putatively justified beliefs, and that the justification of these other beliefs may depend on inferential relations to still further beliefs, and so on, so that a potential regress of epistemic justification looms, with scepticism as the threatened outcome. The foundationalist solution to this problem is that one arrives sooner or later at basic or foundational beliefs: beliefs that are epistemically justified, but whose justification does not derive from inferential relations to any further beliefs and so brings the regress to an end. The defining tenet of a coherence theory of justification is the rejection of this foundationalist solution, the coherentist insisting that any belief (of the kinds to which the theory is applied) depends for its justification on inferential relations to other beliefs and eventually to the overall system of beliefs held by the believer in question. According to the coherentist, the justification of this system of beliefs is logically prior to that of its component beliefs and derives ultimately from the coherence of the system, where coherence is a matter of how tightly unified or interconnected the system is by virtue of inferential connections (including explanatory connections) between its members. Contrary to what this might seem to suggest, coherence theories do not deny that sensory observation or perception plays an important role in justification. What they deny is that this role should be construed in a foundationalist way, insisting instead that the justification of observational beliefs ultimately derives also from considerations of coherence. Specific coherence theories may also add other requirements for justification, thereby departing from a pure coherentism, while still avoiding foundationalism. While the idea of a coherence theory has often played the role of a dialectical foil, developed theories of this kind are relatively rare and are often in serious disagreement among themselves. In this way, coherentism is much less a unified view with standard, generally accepted features, than is foundationalism.