Epistemic Angst by Duncan Pritchard

Epistemic Angst by Duncan Pritchard

This book is a somewhat unusual in that it is a book length treatment of radical skepticism. Radical skepticism, simply stated, is the claim “we can’t be certain that we aren’t just a brain in a vat, and if we can’t be sure of that, how can we be sure of anything?” My impression had always been that people just accepted the first part of it “we can’t be sure” but decided that was a nonstarter for a productive career/happy life 🙂 and proceeded in a let’s act as if that isn’t true manner.

However, in Pritchard’s case, this approach resulted in a state of Epistemic Angst and a desire to find a better solution. Epistemic Angst is the result. While I have some qualms about his conclusions, both the methodology and the results interesting.

For Pritchard, the issue centers upon reconciling our inability to disprove the BIV postulate while retaining our belief in our essential and effective knowledge of the world.

His insight is that radical skepticism conflates two things: 

The first, a closure-based radical skepticism, asserts that rationality commits us to the transitive closure of our rational beliefs. Therefore, if we are unable to rationally disprove the brain in a vat thesis, we can’t rationally defend any of our other beliefs.

The second is an underdetermination/rational-ground based skepticism which holds that there is all too little justification for our perceptually based beliefs. The underlying intuition here is that there is no “real” justification for any of our generalizations about the world. The world could stop rotating, objects could suddenly change color (or even mass) all we really have as a basis for our beliefs is that we don’t have any knowledge of these regularities being violated before, call it the iridescent blue swan problem.

Each of these aspects requires an independent solution, which he proceeds to develop. 

Pritchard addresses the closure-based argument by limiting how far the transitivity of our rational beliefs can be travel. He does this carefully, being sure that the localization of our rational processes doesn’t implicitly precommit us to an overarching “pure rationality” which is not part of our everyday existence. In doing so he analyzes hinge commitments [footnote “questions that we raise and our doubts depend upon the fact that some propositions are exempt from doubt, are as it were like hinges on which those turn.”, hinge commitments are therefore those which we exempt from doubt] which eventually coalesces into an uber hinge commitment 

“the entirely general hinge commitment that one is not radically and fundamentally mistaken in one’s beliefs. Call this commitment the über hinge commitment, and call the proposition endorsed by the über hinge commitment the über hinge proposition.”

“It is not as though, for example, if we had been more careful or thorough in how we acquired rational support for our beliefs then we could have avoided this fate, since there simply is no rational process through which we could have gained rational support for belief in the über hinge proposition”

Accepting this über hinge cuts off the closure based argument by drawing a boundary around our thinking saying, in essence, “we can’t, and won’t, consider that in our current frame”. I find this similar in sprit to the “we’ll proceeded a let’s act as if that isn’t true” approach I mentioned above, but more explicit, bounded, and well grounded.

He addresses the underdetermination/rational-ground based skepticism with what he calls rational support contextualism

“. In this way one could maintain that the epistemic standards relevant to assessing the truth of assertions of knowledge ascription sentences don’t vary from one context of epistemic appraisal to another, but that nonetheless whether or not these assertions express truths is a variable matter. ”

 And epistemological disjunctivism 

“In particular, one can claim that one’s everyday perceptual beliefs enjoy rational support that decisively favors those beliefs over radical skeptical alternatives without thereby having to suppose that one’s hinge commitments to the denials of radical skeptical hypotheses are in the market for (rationally grounded) knowledge.”

Loosely, what this means is that we assess truth vis a vis contrast cases that reflect the type of error that we realistically expect to occur, e.g., when walking down the street we might wonder “is that a Honda or a Toyota,” but it’s unlikely that we would think “is that a Honda or a cleverly disguised nuclear reactor”

Contrast cases vary with context, e.g., our processes for assessing our pragmatic willingness to believe that something is the case differs between our home environment and a haunted house. The truth values don’t change, per se, but our assessment procedure changes since we expect it to be more likely that we might be actively fooled one situation rather than the other.

The implications then fall out in a straightforward manner. The support context for the BIV is radically different from those used in everyday life, since the contrast cases are so radically different. 

While these arguments are convincing in and of themselves, I’m less convinced that they upend radical skepticism and obviate the possibility that we’re in a BIV situation. At most, they give us reason to claim that, if we live in a vat, it is a very good and convincing vat — the best vat imaginable. In fairness, I’m not sure Pritchard thinks that they upend radical skepticism either, more that it offers more viable support for our “as if” actions.