3 For there have risen many who have given to the plain words of Holy Writ some arbitrary interpretation of their own, instead of its true and only sense, and this in defiance of the clear meaning of words. Heresy lies in the sense assigned, not in the word written; the guilt is that of the expositor, not of the text. Is not truth indestructible? When we hear the name Father, is not sonship involved in that Name? The Holy Ghost is mentioned by name; must He not exist?
We can no more separate fatherhood from the Father or sonship from the Son than we can deny the existence in the Holy Ghost of that gift which we receive. Yet men of distorted mind plunge the whole matter in doubt and difficulty, fatuously reversing the clear meaning of words, and depriving the Father of His fatherhood because they wish to strip the Son of His sonship. They take away the fatherhood by asserting that the Son is not a Son by nature; for a son is not of the nature of his father when begetter and begotten have not the same properties, and he is no son whose being is different from that of the father, and unlike it. Yet in what sense is God a Father (as He is), if He have not begotten in His Son that same substance and nature which are His own?
Source: On the Trinity (New Advent)