St Thomas also appeals to Isaias lxvi, 9, in the Vulgate reading. He says: "To whatever meaning the term 'generation' is applied, still the reasoning put in the mouth of God remains firm and stable, that if He gives generation to others, He should not Himself be barren: since a perfection must always exist in a nobler way in the cause than in the things caused." But the reading in Isaias is uncertain, and the application to the eternal generation of the Word has seemed to many, even Catholic commentators, not to suit the text. Revelation is gradual, and must not be antedated.

Of God and His Creatures: 4.2