Augustine of Hippo, On Nature and Grace Chapter 19: Sins of Ignorance; To Whom Wisdom is Given by God on Their Requesting It

He further treats of sins of ignorance, and says that “a man ought to be very careful to avoid ignorance; and that ignorance is blameworthy for this reason, because it is through his own neglect that a man is ignorant of that which he certainly must have known if he had only applied diligence;” whereas he prefers disputing all things rather than to pray, and say: “Give me understanding, that I may learn Thy commandments.” It is, indeed, one thing to have taken no pains to know what sins of negligence were apparently expiated even through divers sacrifices of the law; it is another thing to wish to understand, to be unable, and then to act contrary to the law, through not understanding what it would have done. We are accordingly enjoined to ask of God wisdom, “who giveth to all men liberally;” that is, of course, to all men who ask in such a manner, and to such an extent, as so great a matter requires in earnestness of petition.