In the aftermath of the Council of Chalcedon (451), Christological argumentation developed a sparkling interest in the philosophical problem of universals. This has been prompted by the problematic relationship between Christ’s humanity, which represents the common bond between Him and us, and the individual existence of it, related to His hypostasis. To what extent the common ingredient retains its reality unharmed by the species’ production of its members had been extensively discussed by late antique philosophers who shown a general preference for a mere nominalism with respect to the species. As incomed by the anti-Chalcedonian theological circles, this rationale about the universal has later caused Maximus the Confessor (c.580-662), a famous martyr defender of Chalcedon, to elaborate an original alternative of it, called immanent realism. Mateiescu presents a comprehensive analysis of Maximus’ theory according to which the universal is common to individuals and exists as an indivisible whole in each of them. The argument will show that Maximus employs two principles for his doctrine of immanent realism, one dealing with logic and the other with metaphysics, and that Maximus’ originality consists in their unique combination under the Platonic influence of Dionysius the Areopagite.