While the term itself does not appear in patristic citation, and even the English lexicon knows only the rare verbal form “to enhypostatize” as late nineteenth-century encyclopedic jargon, the doctrinal concept is descriptive of the effort by the sixth-century theologian Leontius of Byzantium* to recast the formula of Chalcedon in an Aristotelian framework under the political pressure from Justinian's demand to settle the Monophysite question. Leontius's term (“intrahypostatic”), from which derives the descriptive heading, is meant to define the unity of substance (hypostasis) one nature may achieve with another, so that its own peculiarity (eidos) is retained. To Leontius and his time the analogy of soul and body, or fire and torch, provided examples, which then permitted the divine-human life of Christ to be described in terms made famous by Cyril of Alexandria.