“I should be sure,” you say, “that the sun and the moon really wish to do us a service if it was possible for them to be unwilling; but they cannot help being in motion. In short, let them halt and discontinue their work.” But see in how many ways this argument may be refuted. It is not true that a man who is unable to refuse is for that reason the less willing to do; nay, the greatest proof of a fixed desire is the impossibility of its being altered. A good man is unable to fail to do what he does; for unless he did it, he would not be a good man. And, therefore, a good man gives a benefit, not because he does what he ought to do, but because,it is not possible for him not to do what he ought to do. Besides, it makes a great difference whether you say: “It is not possible for him not to do this,” because he is forced to do it, or “It is not possible for him to be unwilling.” For, if he is compelled to do it, I owe my benefit, not to him, but to the one who forces him; if he is compelled to wish to do it for the reason that he finds nothing better that he wishes to do, it is a case of the man forcing himself; so, while, in the one case, I should not be indebted to him on the ground that he was forced, in the other, I am indebted to him on the ground that he forces himself.
“Let them cease wishing,”8 you say. At this point the following question should occur to you. Who is so crazy as to deny that an impulse that is in no danger of ceasing and being changed into the exact opposite can be a desire, when, on the contrary, no one must appear more surely to have desire than one whose desire is so completely fixed as to be everlasting?9 Or, if even he who is able at any moment to change his desire may be said to have desire, shall not he whose nature does not admit his changing a desire appear to have desire?