Nicephorus Blemmydes on the Holy Trinity and the Paraconsistent Notion of Numbers: A Logical Analysis of a Byzantine Approach to the Filioque

The paper deals with the most controversial - in the modern scholarly discussion - episode within the Byzantine polemics on the Filioque, Nicephorus Blemmydes‘ acknowledgement of proceeding of the Spirit through the Son providing that the Son be considered as generated through the Spirit. The logical intuition behind this theological idea is explicated in the terms of paraconsistent logic and especially of a kind of paraconsistent numbers called by the author “pseudo-natural numbers”. Such numbers could not be interpreted via the notion of ordered pair. Instead, they imply a known (first described by Emil Post in 1941) but still little studied logical connective ternary exclusive OR.