The Anathemas of the Second Council of Constantinople, No. 7

If anyone using the expression, "in two natures," does not confess that our one Lord Jesus Christ is made known in the deity and in the manhood, in order to indicate by that expression a difference of the natures of which the ineffable union took place without confusion, a union in which neither the nature of the Word has changed into that of the flesh, nor that of the flesh into that of the Word (for each remained what it was by nature, even when the union by hypostasis had taken place); but shall take the expression with regard to the mystery of Christ in a sense so as to divide the parties, let him be anathema. Or if anyone recognizing the number of natures in the same our one Lord Jesus Christ, God the Word incarnate, does not take in contemplation only the difference of the natures which compose him, which difference is not destroyed by the union between them -- for one is composed of the two and the two are in one -- but shall make use of the number two to divide the natures or to make of them persons properly so called, let him be anathema.