The Use of Philosophical Terms ousia, substantia and Their Derivations in Dogma

The present study clarifies historical and etymological origins of the terms ousia and homoousios, substantia and transsubstantiatio, back to the oldest written, literary, and philosophic traces. In general it elucidates also the authentic way of application of these terms by the magisterium wherever they have been used in the Catholic dogma. It strives to show not only the historic origins but also the circumstances of choice of certain terms for particular dogmatic formulae while these same terms are also known to be the terms of various philosophic systems. This goal was achieved mainly by using critical edition of the ecumenical councils but especially by analysis of documents, which retrospectively clarify, characterize and authentically interpret these formulations. Problematic aspects of the discussed terms are also spotted, and grounds of interpretation theories explained. This study also proves that the Church's magisterium at the ecumenical councils did not identify with any historic philosophic system, although some terms, which were used by the council in its texts can also be found in some philosophical schools. However, although philosophical propositions are not proper object of the Divine Revelation, it is necessary, with regard to the linguistic, logical and metaphysical contents of the historical Divine Revelation, to seek many -both implicit and explicit- philosophic formulations, principles and prerequisites which are inextricable from the Revelation itself. If this Revelation is to have meaningful and permanent contents, we have to assume, too, consistency of its philosophical infrastructure.

Keywords: philosophy; dogma; formulation of dogma; ousia; homousios; substance; transubstantiation