Summa contra Gentiles1.95 Chapter XCV. That God cannot will evil

From what has been said it can be proved that God cannot will evil.

For the virtue of a thing is that by which one produces a good work. Now every work of God is a work of virtue, since His virtue is His essence, as we have shown above. Therefore He cannot will evil.

Again. The will never tends towards evil unless there be an error in the reason, at least as regards the particular object of choice. For since the object of he will is an apprehended good, the will cannot tend towards an evil unless, in some way, it is proposed to it as a good; and this cannot be without an error. Now there can be no error in the divine knowledge, as we have shown. Therefore God's will cannot tend to evil.

Moreover. God is the sovereign good, as was proved above. Now the sovereign good does not suffer the company of evil, as neither does the supremely hot suffer an admixture of cold. Therefore the divine will cannot be inclined to evil.

Further. Since good has the aspect of end, evil cannot be an object of the will except the latter turn away from its end. But the divine will cannot turn away from its end, because He cannot will anything except by willing Himself, as we have proved. Therefore He cannot will evil.

It is therefore evident that in Him free-will is naturally established in good.

This is expressed in the words of Deut. xxxii. 4: God is faithful and without any iniquity, and Habac. i. 13: Thy eyes are... pure... and Thou canst not look on iniquity.

Hereby is confuted the error of the Jews who assert in the Talmud that God sins sometimes and is cleansed from sin; and also of the Luciferiani who say that God sinned incasting out Lucifer.