Representing Uncertainty with Expanded Ueberweg Diagrams

Euler diagrams often require several figures to adequately represent propositions and syllogisms. Euler’s followers, notably Friedrich Ueberweg, endeavored to overcome this difficulty with the use of dotted lines to express uncertainty about the relation between the terms of a proposition. Subsequently, Venn regarded such attempts as ineffectual and went to construct his own celebrated scheme. In this paper, we argue that Ueberweg’s method could be expanded to meet Venn’s expectations, and hence, produce alternative Venn-like diagrams.