50 For although the weakness of the understanding might hinder the perceptions of a man devoutly disposed, so that, even after this explanation, he might fail to grasp the meaning of “creation,” nevertheless, even the letter of the Apostle's saying, when he applies the term “making” to a true birth, should have sufficed for a sincere, if not intelligent, belief, that the term “creation” was designed to conduce to a belief in generation. For when the Apostle was minded to assert the birth of One from one Parent, that is to say, the birth of the Lord from a virgin without a conception due to human passions, he clearly had a definite purpose in calling Him “made of a woman,” Whom he knew and had frequently asserted to have been born.
He desired that the 'birth' should point to the reality of the generation, and the 'making' should testify to the birth of One from one Parent; because the term 'making' excludes the idea of a conception by means of human intercourse, it being expressly stated that He was made of a virgin, though it is equally certain that He was born and not made. But see, heretic, how impious you are. No sentence of prophet, or evangelist, or apostle has said that Jesus Christ was created from God, rather than born from Him: yet you deny the birth, and assert the creation, but not according to the Apostle's meaning, when he said that He was made, lest there should be any doubt that He was born as One from one Parent.
You make your assertion in a most impious sense, implying that God did not derive His being by way of birth conveying nature; although a creature would rather have come into being out of nothing. This is the primary infection in your unhappy mind, not that you term birth a creating, but that you adapt your faith to the idea of creation instead of birth. And yet while it would mark a poor intellect, still it would not mark a man entirely undevout, if you had called Christ created, in order that men might recognise His impossible birth from God, as being that of One from One.
Source: On the Trinity (New Advent)