3.  Consider well, my excellent friend, that the falsifiers of the truth, who have introduced the Arian schism as an innovation on the sound faith of the Fathers, advance no other reason for refusing to accept the pious opinion of the Fathers than the meaning of the homoousion which they hold in their wickedness, and to the slander of the whole faith, alleging our contention to be that the Son is consubstantial in hypostasis.  If we give them any opportunity by our being carried away by men who propound these sentiments and their like, rather from simplicity than from malevolence, there is nothing to prevent our giving them an unanswerable ground of argument against ourselves and confirming the heresy of those whose one end is in all their utterances about the Church, not so much to establish their own position as to calumniate mine.  What more serious calumny could there be?  What better calculated to disturb the faith of the majority than that some of us could be shewn to assert that there is one hypostasis of Father, Son, and Holy Ghost?  We distinctly lay down that there is a difference of Persons; but this statement was anticipated by Sabellius, who affirms that God is one by hypostasis, but is described by Scripture in different Persons, according to the requirements of each individual case; sometimes under the name of Father, when there is occasion for this Person; sometimes under the name of Son when there is a descent to human interests or any of the operations of the œconomy; Vide notes, pp. 7 and 12.  On Sabellius, cf. note on Letter ccxxxvi. and sometimes under the Person of Spirit when the occasion demands such phraseology.  If, then, any among us are shewn to assert that Father, Son and Holy Ghost are one in substance, τὸ ὑποκείμενον. while we maintain the three perfect Persons, how shall we escape giving clear and incontrovertible proof of the truth of what is being asserted about us?