Jonathan Dixon

Conciliatory views of peer disagreement (aka Conciliationism) have repeatedly been challenged on the grounds that they are epistemically self-undermining. Recently, Dixon (2024) argues that this challenge is worse than previously thought: it is (almost certainly) permanent and this provides strong reason to abandon Conciliationism as (almost certainly) hopeless. In response, Justin (2025, Episteme) argues that the self-undermining challenge and Dixon’s arguments, at best, only apply to the belief-suspension versions of Conciliationism but not to degree-of-belief (aka credal) versions of Conciliationism. Thus, not only can Conciliationists largely avoid the self-undermining challenge but, contra Dixon, this challenge also does not provide adequate reason to abandon Conciliationism as hopeless. This paper argues that not only can the self-undermining challenge be reformulated to apply to credal versions of Conciliationism, this reformulated challenge extends and further supports Dixon’s pessimism: because there (almost certainly) is or will be peer disagreement on any way of responding to this reformulated challenge, any response (almost certainly) be defeated by the very view it is attempting to defend. Thus, credal Conciliationism is also (almost certainly) permanently self-undermining and there is (almost certainly) still no hope for Conciliationism.

[For a Symposium on Kevin McCain’s _Explanatory Solutions to Skeptical Problems_. Please cite published version.] In Explanatory Solutions to Skeptical Problems (OUP, 2025), McCain aims to show that his preferred view of justification, which he motivates and defends in previous work (Appearance & Explanation (OUP, 2021)), can be used to adequately respond to a host of skeptical problems. I will focus on evaluating how effective McCain’s account of justification is in responding to one kind of skepticism: Cartesian external world skepticism. I argue that McCain’s response either fails or needs more argumentation to be convincing. While I disagree with much of McCain’s way of responding to the arguments for Cartesian skepticism, I can recommend this book to anyone who is interested in skepticism, explanatory inference, and – more generally – good philosophy books.

The Cartesian arguments for external world skepticism are usually considered to be significant for at least two reasons: they seem to present genuine paradoxes and that providing an adequate response to these arguments would reveal something epistemically important about knowledge, justification, and/or our epistemic position to the world. Using only premises and reasoning the skeptic accepts, I will show that the most common Cartesian argument for external world skepticism leads to a previously unrecognized self-undermining dilemma: it either leads to a reductio ad absurdum, or to avoid this reductio the skeptic must accept that this argument is epistemically idle—it does not provide any support for external world skepticism. Either way, this Cartesian argument cannot legitimately threaten or even call into question our beliefs about the external world. And thus, either way, this Cartesian argument for external world skepticism is not epistemically significant—it is not a genuine paradox and adequately responding to it need not reveal anything epistemically important.