39. But the Arians maintain the following: If you say that, as the Father is the only true God, so also is the Son, and confess that the Father and the Son are both of one substance, you introduce not one God, but two. For they who are of one substance seem not to be one God but two Gods. Just as two men or two sheep or more are spoken of, but a man and a sheep are not spoken of as two men or two sheep, but as one man and one sheep.