XII. (81) But it has also happened that Jacob had his name changed to Israel; and this, too, was a felicitous alteration. Why so? Because the name Jacob means “a supplanter,” but the name Israel signifies “the man who sees God.” Now it is the employment of a supplanter, who practices virtue, to move, and disturb, and upset the foundations of passion on which it is established, and whatever there is of any strength which is founded on them. But these things are not brought about without a struggle or without severe labour; but only when any one, having gone through all the labours of prudence, then proceeds to practise himself in the exercises of the soul and to wrestle against the reasonings which are hostile to it, and which seek to torment it; but it is the part of him who sees God not to depart from the sacred contest without the crown of victory, but rather to carry off the prize of triumph. (82) And what more flourishing and more suitable crown could be woven for the victorious soul than one by which it will be able acutely and clearly to behold the living God? At least a beautiful prize is thus proposed for the soul which delights in the practice of virtue, namely, the being endowed with sight adequate to the clear comprehension of the only thing which is really worth beholding.
XIII. (83) 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 practice; (84) for the man who is improved by instruction, having received a happy and virtuous nature, uses that virtue alone which, by means of memory co-operating with it, implants in him an absence of forgetfulness, so that he comprehends and takes firm hold of all the things which he has once learnt; but he who practices virtue, since he is continually exercising himself, stops to take breath, and relaxes his efforts for a while, collecting himself and recovering the vigour which was a little impaired by his exertions, just as those men do who have oiled their bodies for the contests in the arena. For these men, also, labouring at their training exercises, in order to prevent their powers being utterly broken down, anoint themselves with oil on account of the violent and continued nature of their exercise. (85) Then the man who is improved by instruction, having an immortal monitor, receives from him a harmonious and imperishable advantage, without suffering any change; but the practiser of virtue is impelled to action by his own inclination alone, and he exercises himself in it, and labours at it in order to change that passion, which is akin to a created being; and even if he attains to perfection, he still, being fatigued, returns to his ancient kind of labour; (86) for he is more inclined to endure toil, but the other is more fortunate, for he has another person as a teacher. But this man, by his own unassisted efforts, investigates, and inquires, and pushes his examination, investigating the mysteries of nature with great earnestness, and exerting continual and incessant labour. (87) For this reason God, who never changes, altered the name of Abraham, since he was about to remain in a similar condition, in order that that which was to be firmly established might be confirmed by him who was standing firmly, and who was remaining in the same state in the same manner. But it was an angel who altered the name of Jacob, being the Word, the minister of God; in order that it might be confessed and ascertained, that there is none of the things whose existence is subsequent to that of the living God, which is the cause of unchangeable and unvarying firmness. … but of that harmony which, as in a musical instrument, contains the intensity and relaxation of sounds so as to produce an artistical combination of melody.