St. Thomas Aquinas's confrontation with Neoplatonic thought in three *commentaries, and in the “Treatise on Separate Substances”

John J Stefanczyk, Fordham University


Aquinas's commentaries on the de Hebdomadibus of Boethius, on The Divine Names of Dionysius, and on the anonymous Book of Causes, as well as his late text Treatise on Separate Substances have been described as those writings in the Thomistic corpus that best exhibit the Neoplatonic elements in his thought. However, the claim of a partial borrowing of Neoplatonic doctrines is controversial due to some assertions in recent scholarship postulating the inseparability of specific areas of Neoplatonic doctrine from their larger context, notably negative theology and ontological hierarchy as allegedly rooted in a meontological doctrine of God. Here a careful reading of salient passages from these four Thomistic texts aims to demonstrate the essential correctness of Aquinas's reinterpretation of key Neoplatonic doctrines. However, hermeneutical presuppositions of this reading that need to be taken into account include Thomas's method of benign interpretation, whereby he frequently attempts an alternative reading of an authoritative text (at variance with the literal sense) that is not directly in conflict with his own philosophical and theological tenets. In other cases, he reinterprets a useful aspect of a rejected position in order to develop his own thought on some issue. Nevertheless, he does at times make more direct criticisms of Platonic doctrines from the perspective of his own metaphysics. Important examples of this procedure include a reinterpreted metaphysical participation which emphasizes the unity of the substance as indicative of the unity of the transcendent cause. This is a doctrine that Aquinas invokes to emphasize the direct creation of the human soul and of the separate substance, against Neoplatonic claims of mediated causality. Another significant doctrine Aquinas applies in this polemic is the Maxime Communia or Transcendentals, which he opposes to a Platonic meontological conception of the first principle. The fundamental idea of an ontological hierarchy, which for Aquinas is best explained by analogous modes of esse including cognitional being, becomes part of an argument against Platonic separatism, for he argues this involves an unwarranted projection from cognitional to real being. Finally, the implications of the concept of esse found in this context are considered in the light of discussions in Thomistic literature in order to distinguish it from possible parallels in Neoplatonic thought.

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Recommended Citation

Stefanczyk, John J, "St. Thomas Aquinas's confrontation with Neoplatonic thought in three *commentaries, and in the “Treatise on Separate Substances”" (2006). ETD Collection for Fordham University. AAI3201139.