 When acquaintance with the fact that P is part of what constitutes my foundational justification for believing P, there is a trivial sense in which my foundational justification is infallible. I can’t be directly acquainted with the fact that P while I believe P falsely. However, most contemporary foundationalists are fallibilists about foundational justification: they hold that one could be foundationally justified in believing propositions that are false. It seems plausible that I could be justified in believing, for example, that I am experiencing a mild pain when in fact I am experiencing an itch, or that I could be justified in believing I am experiencing a specific shade of color when I am in fact experiencing a slightly different shade. Even some acquaintance theorists want to allow for some fallible foundations. For example, Fumerton (1995) holds that one can be noninferentially justified in believing P by virtue of being directly acquainted with a fact very similar to, but ultimately different from, the fact that P (the fact that makes P true). Such an acquaintance theory could allow for the possibility of a foundationally justified but false belief that P. Huemer (2007), Poston (2010), and Tucker (2016) argue, however, that classical foundationalists have difficulty accommodating fallible foundational beliefs. For some replies, see Fumerton (2010 and 2016), and Hasan (2013).