 In addition to these general commonalities in Dedekind’s and Frege’s versions of logicism, the two thinkers also agreed on a methodological principle encapsulated in the following remark by Dedekind: In science, and especially in mathematics, “nothing capable of proof ought to be accepted without proof” (Dedekind 1888a, preface). This principle ought to be adhered to not so much because it increases certainty. Rather, it is often only by providing an explicit, detailed proof for a result that the assumptions on which it depends become evident and, thus, its range of applicability established. Both Frege and Dedekind had learned that lesson from the history of mathematics, especially developments in geometry, algebra, and the calculus (see Reck 2013, building on Wilson 1992, 2010, Tappenden 1995, 2006, Ferreirós 1999, and Detlefen 2011).