The fact of evil has worried theists for a long time. The earliest clear statement of this worry is perhaps to be found in the book of Habbakuk: ‘Thou art of purer eyes than to behold evil, and canst not look on iniquity: wherefore lookest thou upon them that deal treacherously, and holdest thy tongue when the wicked devoureth the man that is more righteous than he?’ (i, 13). More precisely formulated, it comes to this: if God is good and omnipotent, why evil ? From his goodness it would follow necessarily that he does not will evil and from his omnipotence that he could prevent it; why then should it occur? Theists have attempted to escape from this dilemma by means of an argument which turns on the claim that human beings are, to some degree at any rate, free to choose and act as they will. They are free to do good or evil; frequently they choose the latter and that is why evils, or at least many of them, occur. This human freedom, however, is a necessary condition of personality and, as such, a great good; so it is perfectly consistent with the goodness of God that he should will it. But what of his omnipotence? The point of the argument is that God has to allow those evils which result from men making evil choices, and this certainlylooks, at first blush, like a limitation of his power. But, we are assured,it is not really a limitation because all it amounts to is that God cannot do the logically impossible, viz., make beings who, at one and the same time, are both free to do what they will and pre-determined to do good.To deny that God can do the logically impossible, of course, is not to den his omnipotence; it is merely to point out that there are some things which it would not make sense to say that he had done.