The main argument of the Arians was that our lord was a Son, and therefore was not eternal, but of a substance which had a beginning. [Prolegg. ch. ii. §3 (2) a.] Accordingly Athanasius says, ‘Having argued with them as to the meaning of their own selected term “Son,” let us go on to others, which on the very face make for us, such as Word, Wisdom, &c.’