The theological implications of a relational definition of the sign

Roger Bacon's definition and description of the sign in De Signis can only be understood in relation to its theological background, and more specifically that of sacramental theology. Starting with the Augustinian definition in De doctrina christiana, the nature of the sign is at the heart of the position defended by Bérenger de Tour in the ^{eleventh-century} Eucharistic quarrel, and will remain so until the Logique de Port-Royal. When the question of the meaning of the sacramental sign is joined by that of its efficacy, discussions focus on the virtus that transforms the thing into a sign: is it of a substantial nature(quid), or of a relational nature(ad aliquid)? Here again, Augustine is the source invoked, with the example of the coin that becomes a prize(ut denarius fit pretium), which comes up in discussions on divine attributes. The dual relationship of the sign to the interpreter and the signified in §1 of De signis is discussed by theologians, notably Richard Fishacre and Bonaventure. Bacon's emblematic example of the circulus vini is a counterpoint to the latter.