15 But the fiery zeal of this heresy is such that it cannot restrain itself from passionate outbreak. In its effort to prove, in conformity with its assertion that He did not exist before He was born, that the Son was born from the non-existent, that is, that He was not born from God the Father to be God the Son by a true and perfect birth, it winds up its confession by rising in rage and hatred to the highest pitch of possible blasphemy:— “As to such phrases as from Him, and from the womb, and I went out from the Father and have come, if they be understood to denote that the Father extends a part, and, as it were, a development of that one substance, then the Father will be of a compound nature and divisible and changeable and corporeal, according to them; and thus, as far as their words go, the incorporeal God will be subjected to the properties of matter.”
The defence of the true faith against the falsehoods of heresy would indeed be a task of toil and difficulty, if it were needful for us to follow the processes of thought as far as they have plunged into the depths of godlessness. Happily for our purpose it is shallowness of thought that has engendered their eagerness to blaspheme. And hence, while it is easy to refute the folly, it is difficult to amend the fool, for he will neither think out right conclusions for himself, nor accept them when offered by another. Yet I trust that they who in pious ignorance, not in wilful folly bred of self-conceit, are enchained by error, will welcome correction. For our demonstration of the truth will afford convincing proof that heresy is nothing else than folly.
Source: On the Trinity (New Advent)