Abstract

The doctrine of the Holy Trinity requires the joint truth of the statements that there is a unique and simple God, and that there are three distinct Persons each of which is God. Saint Augustine posed the question what entities would have to exist, and how would they have to be related, in order for this doctrine to be internally consistent. The present book examines the attempts by ten leading philosophers (Augustine himself, Boethius, Abelard, Gilbert, Lombard, Bonaventure, Albert, Aquinas, Scotus and Ockham) to answer Augustine's question. Subsidiary questions include the nature of divine simplicity, the divine perfections, the personal relations and their associated properties, and the interrelation between the abstract and the concrete within the Godhead. Each one of the historical theories of the Trinity is presented as a semantic model postulating a domain that, as needed, comprises a number of substances and non-substances. In each case, the theory's terms (e.g. the names of the Persons, and of the divine perfections, etc.) are assigned to elements in the domain. The elements to which the names apply essentially are designated as such. As needed, the abstracts of the names are also assigned elements in the domain. Various pairs of elements in the domain are connected as correlatives, or as abstract and concrete, or by way of substantial predication. These models allow for comparisons between different theories, and provide a means of checking a theory's consistency.