It is of the essence of the New Testament, as the religion of the Incarnation, to be final and catholic: on the other hand, it is of the essence of the Old Testament to be imperfect because it represents a gradual process of education by which man was lifted out of depths of sin and ignorance. That this is the case, and that in consequence the justification of the Old Testament method lies not in itself at any particular stage, but in its result taken as a whole, is a thought very familiar to modern Christians[279]. But it is important to make plain that it was a thought equally familiar to the Fathers of the Christian Church. Thus S. Gregory of Nazianzus, speaking of God's dealings with the Jews of old, describes how, in order to gain the co-operation of man's good will in working for his recovery, He dealt 'after the manner of a schoolmaster or a physician, and while curtailing part of their ancestral customs, tolerated the rest, making some concession to their tastes, just as physicians make their medicines palatable that they may be taken by their patients. For men do not easily abandon what long custom has consecrated. Thus the first law, while it abolished their idols, tolerated their sacrifices; the second, while it abolished their sacrifices, allowed them to be circumcised: then when once they had accepted the removal of what was taken from them, they went further and gave up what had been conceded to them--in the first case their sacrifices, in the second their practice of circumcision--and they became instead of heathens, Jews, instead of Jews, Christians, being betrayed as it were by gradual changes into acceptance of the Gospel[280].' Again, S. Chrysostom explains how it is the very merit of the Old Testament that it has taught us to think things intolerable, which under it were tolerated. 'Do not ask,' he says, 'how these (Old Testament precepts) can be good, now when the need for them is past: ask how they were good when the period required them. Or rather, if you wish, do inquire into their merit even now. It is still conspicuous, and lies in nothing so much as what now enables us to find fault with them. Their highest praise is that we now see them to be defective. If they had not trained us well, so that we became susceptible of higher things, we should not have now seen their deficiency.' Then he shews how under the old law swearing by the true God was allowed to avoid swearing by idols, the worse ill. 'But is not swearing at all of the evil one?' he asks. 'Undoubtedly, now, after this long course of training, but then not. And how can the same thing be good at one time and bad at another? I ask rather, how should it not be so, when we have regard to the plain teaching of the fact of growth in all things, fruits of the earth or acquirements of man? Look at man's own nature; the food, the occupations which suit his infancy, are repulsive to his manhood. Or consider facts of history. All agree that murder is an invention of