The Problem of the Criterion is not just a perplexing philosophical problem, an exercise in logical thinking, or something to propose to a classroom filled with students, but a practical problem that can affect every consumer every day.
The problem may be generally stated as follows (following Roderick Chisholm): 1) Which propositions are true? 2) How can we tell which propositions are true? What are the criteria of knowledge?
These are not questions concerning the nature of truth itself. These are epistemic questions, so that one theoretically might have the answers to 1 and 2 without having a theory of truth at all.
It seems, upon closer inspection, that we cannot answer (1) unless we know the answer to (2), but can’t answer that until we know the answer to number one, leaving us in a skeptical whirl of confusion. In other words, we can’t know if a proposition is true unless we know what the standard for truth is for that particular proposition, but how do we know what that standard is to be if we can’t know what is true? There seems to be a lot of hand-wringing over this aspect of the Problem of the Criterion, with some attempted “solutions” to it, including Explanatory Particularism, Coherentism, and Applied Evidentialism. The Stoics come in for some criticism here, but their approach to this problem was pretty simple, if unsatisfactory to the philosophic community. In their quest for “quietude” they held their acceptance of any proposition at arm’s length, skeptically viewing it as, perhaps unverified but workable, since they also believed that, practically, they had to live a life in the daily world everyone else (including themselves) inhabits. Following that approach, I offer such a pragmatic effort with an example. […]