On the Unchangeableness of God (64-66)

since a severe master is a beneficial thing for untractable and foolish servants; for they, fearing his inflictions and his threats, are chastened by fear, in spite of themselves. Let, therefore, all such men learn false terrors, by which they may be benefited if they cannot be led into the right way by truth.

For in the case of men who are afflicted with dangerous illnesses, the most legitimate physicians do not venture to tell them the truth, knowing that by such conduct they will be rendered more desponding, and so that the disease will not be cured; but that by contrary language and comfort, they will bear the disease which presses upon them more easily, and the illness will be more likely to be allayed.

For what man in his senses would say to a patient under his care, "My good man, you shall have the knife applied to you, and cautery, and your limbs shall be amputated," even if such things were absolutely necessary to be endured? No man on earth would say so. For if he did, his patient would sink in his heart before the operations could be performed, and so receiving another disease in his soul, more grievous than that already existing in his body, he would resolutely renounce the cure; but if, on the other hand, through the deceit of the physician he is led to form a contrary expectation, he will submit to everything with a patient spirit, even though the means of his salvation may may be most painful.