[83] [cap.13] And it is worth while here to raise the question why Abraham, from the time that his name was changed, is always thought worthy of this same appellation, and is no longer called by his former name; but Jacob, who is also called Israel, is nevertheless called Jacob too, as he was before the change of his name; and, indeed, is called Jacob oftener than Israel. We must say, then, that these facts are characters by which it is seen that the virtue which is taught differs from that which is acquired by practise;