Thus he says here also Eccl. 2:14. The wise man has his eyes in his head. That is, they are not only prudent administrators of affairs, but circumspect, diligent, and watchful. They do indeed see how affairs are to be administered, but they cannot bring about the outcome. The fool, on the other hand, does not have his eyes in his forehead, because he is carried along by temerity and boldness. Eventually the affairs of both are decided by luck and fortune, that is, by God’s determination of the outcome, and not by either our counsel or our temerity. Both of them sometimes fall and sometimes prosper. But God does not want this to become the basis of rules. For the creatures are not in our hand, but in God’s, who gives them to us to use and who through us does what He wishes. What we add on our own, however, when we wish to determine this use by our own counsels and efforts, is in vain. Therefore he instructs us not to trust in our own wisdom and counsel but to do what He has given us to do; if it does not succeed, we should commit it to God. (Luther’s Works, v.15 p.40)

Eccl. 2:12.  So I turned to consider wisdom and madness and folly; for what man can imitate the King who has previously made him?  Then I saw that wisdom excels folly as light excels darkness. The wise man has his eyes in his head, but the fool walks in darkness; and yet I perceived that one fate comes to all of them.

Another experience proves that everything is vanity, namely, the efforts and plans of men. “Whatever happened to me,” he says, “I saw that it also happened to others. My counsels and even my wisdom were vain and useless; they did not have the success that I wanted. I observed the same thing in others as well. I observed the wisdom and the madness of others and compared them with each other. I saw that some men behave very wisely and attempt many things prudently. I also saw mad fools acting without any plan. Yet their folly and madness was somehow lucky and successful, while the plans of the wise men were utterly useless and the wise men themselves were so unfortunate that the madness merited the proverb ‘Fortune helps the bold.’ ” ….  In short, a thing is not decided by the wisdom of the wise nor by the temerity of the foolish, so that the counsels of the wise are made foolish and we do not glory in ourselves. Thus in war victory does not come immediately, even though the army may be highly trained and everything may be very wisely thought out, as some years ago certain victory was expected by the French over the emperor, but the opposite came out.

Therefore he says: You see that the foolish succeed as well as the wise, so that there is no difference apparent between the wise man and the madman as far as success is concerned, in fact, so that it seems that there is no God who would allow things to be carried on so madly. But Solomon answers: “No, wisdom is far more excellent than folly,” even though it is true that human wisdom does not accomplish things but God Himself accomplishes them. God is able by His wisdom to accomplish whatever He wishes, but man does not accomplish it. For God has not only wisdom but also the power to accomplish it, so that what He has decreed succeeds; man is not able to do this. In short, the counsel of God is not deceived, but the counsels of men, even of wise men, are deceived. Therefore he correctly says:

Eccl. 2:13. Then I saw that wisdom excels folly as light excels darkness. Wisdom is indeed a good thing; nevertheless, it lacks power and cannot accomplish things or decide events. (Luther’s Works, v.15 p.38-39)