Ecclesiastes-Songs of Songs

...is an example of Ancient Near Easter "dialectic" or dialogue literature. A good foundation to begin for Ecclesiastes is our essay on proverbial literature and on the book itself, plus this item on authorship. Also useful is this item [off site] about allegations of borrowing from pagan literature.

Ecclesiastes 1:4: Will the earth pass away, or not?

Ecclesiastes 1:9: This verse tells us there is nothing new under the sun; the silliest skeptics ask how this can be so in light of the "newness" of the atomic bomb and men walking on the moon. This objection does not appreciate the proverbial nature of Ecclesiates; this verse merely emphasizes the repetitive nature of life's undertakings and the relative futility of effort. This is no more than a rhetorical absolute typical of the ANE wisdom literature.

Ecclesiastes 3:19-21, 9:5: Are these verses contrary to the doctrine of resurrection?

Ecclesiastes 9:5: Does this verse teach "soul sleep"?

Ecclesiastes 11:9: Is this contradictory to Num. 15:39? No, because of the purpose of Ecclesiates as a dialogue; 11:9 is the "negative" side -- see here.