17. Now let us look at the words, "So then it is not of him that willeth, nor of him that runneth, but of God that hath mercy." They who take hold of the passage say, "If it is not of him that willeth, nor of him that runneth, but of God that hath mercy," salvation does not depend upon ourselves, but upon the way they are constituted by Him Who makes them what they are, or on the choice of Him Who hath mercy when He pleases! We must ask the objectors this question: Is the willing that which is good a good or a bad thing? and the running of the man who wishes to reach the goal by zealously pursuing that which is good, is this deserving of praise or blame? If they tell us that it deserves blame, their answer will be absurd, for the saints will and run, and, of course, herein do nothing deserving blame. If they say that to will that which is good is good, and to run after that which is good is good, we will ask how the perishing nature wills the better course; for it is like a bad tree bearing good fruit, if willing the better course is really good. And, thirdly, they will say that to will that which is good and run after that which is good belongs to the class of things indifferent, and is neither good nor bad. In reply to this it must be said that if willing the good and running after the good is a thing indifferent, then its opposite is also a thing indifferent, that is to say, willing that which is evil and running after that which is evil. But, in fact, to will that which is evil and run after that which is evil, is not a thing indifferent. Therefore, to will that which is good and run after that which is good, is not a thing indifferent.