Or “a shining body”—lumen, not lux, as in other places of this passage. St. Ambrose probably was unaware that “radiance” or “effulgence” from an incandescent or otherwise shining body is clue to the presence of the atmosphere, so that his analogy requires modification when bodies shining in vacuo come into the account. But with regard to these it may be urged that the shining of the body may be taken as the sole object of consideration, whilst it is fully admitted that the brightness and the body, though separated for purposes of mental treatment and thought, are not so in fact and actual reality. In the Book of Wisdom, vii. 26, the Divine Wisdom is called “the brightness of everlasting Light” (ἀταύγασμα φωτὸς αϊδίου)—These texts would naturally suggest the ‘Light of Light’ (φῶς ἐκ φωτός,) of the Nicene Creed. The analogy of light and radiance is employed by many of the Fathers in maintaining the doctrine of the Church, see Alford’s note on Heb. i. 3.