The Metaphysics of Primary Plurality in Achard of Saint Victor

The conditions for an investigation of Achard of Saint Victor (who died in 1171) have only recently become available. Now the discovery of a very significant turn in the history of twelfth-century thought is open to examination. The author focuses on Achard's claim concerning an ontologically primary plurality. In the very title of Achard's main treatise, De unitate Dei et pluralitate creaturarum, it is the word 'et' that joins together unity and plurality, expressing the core of Achard's ontological insight, whereby a plurality is said to be true if it is grounded in absolute unity. That is to say, this plurality is not derived from unity (as would be assumed in an emanative account of plurality) but rather "coheres" with unity. Unity, likeness, and equality are the three terms that dialectically constitute the primary plurality. In this sense, true plurality is plurality without difference, without alterity and is thus convertible with identity. The essay examines (a) Achard's doctrine of true plurality as multiple unity, (b) its application to the question of the Trinity and (c) its application to the question of the plurality of creatures and the nature of individuation.