It is no trifling matter that even before the merit of good works, the soul has received a natural power of judgment by which it prefers wisdom to error and peace to difficulty, so that it achieves these not simply by being born, but instead by its own endeavor. If the soul is not willing to act, it may justly be regarded as sin, for it has not put to good use the faculty that it received. For although it was born in ignorance and difficulty, nevertheless it is not compelled by necessity to remain in the state in which it was born. [On Free Choice of the Will, III.xx, p. 131-132]
If we are created so that we prefer wisdom to error, which is a good thing, it cannot be said to be evil or wicked when a man pursues wisdom. Of course it is possible for a man to “fail” to find wisdom deliberately, by prejudiced searching or deliberately hiding from it; but if we have free will as St. Augustine insists throughout the book, then it cannot be the case that we are compelled to shun wisdom.
This isn’t to say, of course, that a man may merit initial justification. It is to say that it is irrational to suggest that non-Christians never do good; it is to say that to hold that the non-Christian cannot do good is decidedly not an Augustinian view: “even before the merit of good works” a man has some powers for good. They cannot save him, of course, but that is not why God gave them to us.