Forthcoming in Synthese. All citations should be to the published version. Background Beliefs and Plausibility Thresholds: Defending Explanationist Evidentialism Matt Lutz “All reasonings concerning matter of fact seem to be founded on relations of cause and effect. By means of that relation alone we can go beyond the evidence of our memory and senses.” – David Hume Explanationist Evidentialism (EE) is the conjunction of evidentialism and explanationism. According to evidentialism, a belief that P is justified for S if and only if P fits S's total evidence E. And according to explanationism (at a first pass), a proposition P is justified for a subject S just in case the truth of that proposition is part of the best explanation available to S of some relevant data (Lipton 2004). Supporters of EE also typically accept mentalism, which says that all evidence consists in, or at least supervenes on, an agent's (non-factive) mental states. Putting these three views together, we get the view that a subject is justified in believing a proposition P just in case P is part of the best explanation of S’s non-factive mental states. Thus, for example, EE says that I am justified in believing that there is an apple on the table when I have a visual experience as of an apple on a table because that visual experience is a non-factive mental state that is best explained by there being an apple on the table. EE is a fairly popular view. Explanationism has been defended in detail by Peter Lipton (2004), and the full EE package has received noteworthy defenses by Connee and Feldman (2008), Poston (2014), and McCain (2014a, 2014b), inter alia. As the view has grown in popularity, there have (inevitably) arisen a number of challenges and objections to it. In this paper, I will sketch a version of EE, and show how this version of EE can meet various objections. I will be particularly interested in addressing a pair of new objections to EE from Appley and Stoutenburg (2017) that have not yet been rebutted.