Heidegger's Bible Handbook: Ecclesiastes: Time of Writing
5. It was written by Solomon, having already fallen, but now penitent.
The time of the writing of the book is not wont to be determined in one way. That is was written before his fall, is pleasing to Bellarmine, Bonfrerius, and others in subservience to their hypothesis concerning the apostasy of the Saints. But we have expressed, that the book was written by Solomon after his fall and repentance, Dissertatione de salute Solomonis, thesis 40, proven by eight arguments, with the sophistries of Bellarmine also enervated. And certainly the sum of the whole book is pure lowliness before God, and also confession and deprecation of the vanities and sins, whereby he had made himself obnoxious before God. And, that the Hebrews with great agreement establish that very thing, we have plainly asserted in that place.