Scutum Fidei - Significance

Significance

The main achievement of the Shield of the Trinity diagram is to transfer a large part of the essential "mystery" or "paradox" of the Christian doctrine of the Trinity from the realm of complex verbal philosophical abstractions and esoteric theological vocabulary to the realm of simple logic, as presented in the relatively easily graspable form of a concrete and conveniently compact visual diagram. It is remarkable as a basically successful attempt, roughly 800 years old, to represent a complex set of abstract concepts in precise graphic form (as opposed to many of the near-contemporary attempts of Joachim of Fiore and Raymund Lull, which were not so successful). Thus it is probably one of the oldest meaningful "graphs", in the sense of graph theory (technically, it is a complete graph on 4 vertices, the same as the vertices and edges of a tetrahedron).

Of course, if the diagram is interpreted according to ordinary logic, then it contains a number of contradictions (since the set of twelve propositions listed above is mutually contradictory). However, if the three links connecting the three outer nodes of the diagram to the center node are interpreted as representing a non-transitive quasi-equivalence relation (where the statement "A is equivalent to C" does not follow from the two statements "A is equivalent to B" and "B is equivalent to C"), then the diagram is fully logically coherent and non-self-contradictory. So the medieval Shield of the Trinity diagram could be considered to contain some implicit kernel of the idea of alternative logical systems.

Unlike some other logical or mathematical constructs sometimes offered as analogies for the Trinity (such as the Venn diagram and the cube viewed by inhabitants of a two-dimensional plane), the Shield of the Trinity does not too easily lend itself to interpretations which are non-orthodox from the traditional mainstream Christian point of view.