1704, Thomas Emlyn, “General Remarks on Mr. Boyſe’s Vindication of the True Deity of Our Bleſſed Saviour. To which is added, An Examination of Mr. Boyſe’s (and from him Dr. Waterland’s) Anſwer to the Objection from Mat.24. 36. and Mark13. 32.Of that day knoweth none, not the Son, but the Father only. And alſo A ſhort Reflexion on Mr. Boyſe’s Argument for the Supreme Deity of Jeſus Chriſt, from the Creation of all Things being aſcribed to Him.” (chapter I: ‘That God and his Son Jeſus Chriſt are two diſtinct Beings, the one underived, the other derived’) in The Works of Mr. Thomas Emlyn…in Three Volumes, volume I (4th ed.; 1746; London: printed for John Noon at the White-Hart near Mercers-Chapel in Cheapſide, and for John Whiston, in Fleet-Street), pages 172–173
Beſides, the Scriptures tell us, that God is εἶς or unus, i. e. one perſon. Gal. 3. 19. Luke 12. 29. And not only unum, or one Being, and therefore is no more alius et alius, than aliud et aliud, tho the Trinitarians affirm the firſt, becauſe they would have ſeveral perſons to be one and the ſame being or eſſence, and make a mighty difference between the maſculine and neuter gender, in the uſe of theſe words unus et unum, alius et aliud, when of God the Scripture ſays in the maſculine, that he is but unus, i. e. one perſon according to them.
1913, Joseph Pohle [aut.] and Arthur Preuss [tr.], Christology: A Dogmatic Treatise on the Incarnation (B. Herder), page 125
Thus in the Most Holy Trinity, the Father and the Son are alius et alius, but not aliud et aliud, because, though distinct as Persons, they are absolutely identical in Nature. In Christ, on the other hand, because of His twofold nature, we may distinguish aliud et aliud, but not alius et alius, because He is only one Person.