See this legally free ebook:

  • “His Only Son”: The Truth of the Divinity of Christ, by William F. Robison, S.J. (St. Louis, Mo.; London: B. Herder, 1918). With Imprimatur. Available in various formats (pdf, text, epub, kindle/mobi, etc.) at Internet Archive.

On the Feast of the Transfiguration in the one true Church. For other legally free ebooks, you may access the List of Free eBooks (Arranged by Title) and the List of Free eBooks (Grouped by Subject).

“That admirable and divine unity, therefore, must neither be separated into three divinities, nor must the dignity and eminent greatness of the Lord [Jesus Christ] be diminished by having applied to it the name of creation, but we must believe in God the Father Omnipotent, and on Christ Jesus His Son, and on the Holy Spirit. Moreover, that the Word is united to the God of all, because He says, I and the Father are one; [John 10:30] and, I am in the Father, and the Father is in Me. [John 14:10] Thus doubtless will be maintained in its integrity the doctrine of the divine Trinity, and the sacred announcement of the monarchy.” (Pope St. Dionysius, Against the Sabellians 3 [c. 260 AD])