Jerome : "What gain, then, has the worker in exchange for all his toil? I have observed the task which God has given the sons of man to be concerned with: He made everything beautiful in its time; He has also put an enigma into their minds so that man cannot comprehend what God has done from the beginning to end." The opinion of many other scholars on this passage does not escape me, because in this world God conceded to the teachers of perverse doctrines their true occupation, lest man's idle mind should become slow and while thinking that God's creations are good, yet nonetheless not be able to see them as the natural knowledge of the world. But the Hebrew who taught me the Scriptures explained it in this way: when all things are placed in their own time and there is a time for destroying or building, weeping and laughing, silence and speaking, and others things which are said about time, why do we try to survive in vain and believe the labours of this short life to be perpetual? And according to the Gospel we are not even happy, and it is called wickedness since we think nothing of tomorrow. [Cfr Matth. 6, 34.] For what more are we able to have in this world than continual striving in that toil, which God has given to man, so that one man may gain more by following others, in a situation where he is able to learn and exercise himself? For all that God does is good, but good in his world. It is good to wake and to sleep, but it is not good to be always awake or asleep, since in turn each and every thing can be considered good, when there is need, according to God's plan. Moreover God also created the world to be inhabited by men, so that they should enjoy the variation of time, and not seek the causes nature, how all things are made, why He made this or that grow or change from the beginning of the world until now. — Commentary on Ecclesiastes