Augustine argues in De Fide Rerum Inuisibilium and De Utilitate Credendi that friendship requires some beliefs. While Augustine thinks these beliefs should be grounded in considerable evidence and accompanied by awareness of their epistemic limitations, he also thinks, for reasons often aligning with the views of Stroud (2006) and Keller (2004) , that non-epistemic considerations should limit how high we set the evidentiary thresholds (the amount of evidence we require before believing). Putting Augustine in conversation with Adler and Hicks (2014) elucidates how the beliefs Augustine advocates are possible if one precisely defines the sort of doubt they involve.
Alexander Vega (Sun,) studied this question.