Letter 102: Against the Theopaschites and those who affirm one nature in Christ.
Isidore of Pelusium→Timothy Reader|c. 392 AD|Isidore of Pelusium|Human translated
christology
You profess a philosophical art but pursue a mischievous purpose, healing small wounds while suffering from great ulcers. If, then, you wish to appear a physician in reality, heal your own character first. For it is cold and ridiculous and graceless to attempt to cure others while ignoring your own illness. The true physician examines himself before he examines his patient.
Against the Theopaschites and those who affirm one nature in Christ. Just as sailors hide the hook with bait and thus catch unsuspecting fish, even so wicked allies of heresies, covering their evil designs with fair words, fatally ensnare the more simple-minded[1]. With all care therefore guard your heart lest in any respect you accept Christ’s nature after the Incarnation as an appearance[2]. For assent to one nature involves a denial of the other –(for) either the divine nature is subject to change or our (humanity) is diminished. This is the Charybdis of Manes, by means of which he strove to lead (us) all to Gehenna.
You profess a philosophical art but pursue a mischievous purpose, healing small wounds while suffering from great ulcers. If, then, you wish to appear a physician in reality, heal your own character first. For it is cold and ridiculous and graceless to attempt to cure others while ignoring your own illness. The true physician examines himself before he examines his patient.
Human translation — Roger Pearse (additional translations)