Enhypostasis

The doctrine of the person of Christ is argued with greatest fullness, and he [John of Damascus] evinces no little ingenuity and dialectic skill in treating of the personal unity in Christ's twofold nature (which he conceived as enhypostasis, not anhypostasis, of the human nature in the Logos), […]

When, for instance, theology speaks of Jesus' anhypostasis and his enhypostasis, these ontological terms must be understood in the light of the concrete ways in which Jesus acted and spoke in the name of God, the ways in which he maintained the distinctions between himself and God through his self-abnegation, and how he left others with no impression of pedantry or dogmatism.

The two natures of Christ are two enhypostases but not two hypostases.

Del Colle [Ralph del Colle] introduces the concept of the enhypostasia of the Spirit. This is analogous to the two enhypostases of the Son [Jesus Christ]. First, the Son is generated by the Father immanently, and in the economy of God the Son as a human person comes through generation (from the Virgin's womb). But there is a second enhypostasis of the Son: "The eternal Son now incarnate … in his human nature undergoes an in-personing in the Spirit."