 Following Bolzano (Theory of Science: vol. II, 259–264), most contemporary theories of grounding affirm the irreflexivity of this relation (see Fine 2001: 15; Schaffer 2009: 364; and Rosen 2010: 115). More recently, Fine showed that given certain plausible premises, one may point out counterexamples to irreflexivity (Fine 2010; cf. Krämer 2013), and the issue has been further challenged by Jenkins (2011).