Only this have I found: I have discovered that God made mankind upright, but they have sought out many schemes.”
Solomon had hitherto been proving the vanity of the world and its utter insufficiency to make men happy; now here he comes to show the vileness of sin, and its certain tendency to make men miserable; and this, as the former, he proves from his own experience, and it was a dear-bought experience.
Commenting on Ecclesiastes 7:23-29
Lo, this only have I found, that God hath made man upright,.... The first man Adam, as the Targum and Jarchi interpret it; and not Adam only, but Eve also with him; for these were both made by the Lord, and on the same day, and in the same image, and had the same common name of Adam given them, Gen 1:27; And they were...
The "only" way of accounting for the scarcity of even comparatively upright men and women is that, whereas God made man upright, they (men) have, &c. The only account to be "found" of the origin of evil, the great mystery of theology, is that given in Holy Writ (Gen. 2:1-3:24).