Do the dead know nothing? What does Ecclesiastes 9:5 mean?

They don't contradict — they're answering different questions. Once you see the frame Ecclesiastes sets up, the tension dissolves.

The Preacher uses a signature phrase throughout the book: "under the sun" (tachat hashemesh, H8478 + H8121). It appears 29 times in Ecclesiastes, and it marks the boundary of what he's discussing — everything that can be observed within the natural order of earthly life. When he says in chapter 9 that the dead know nothing, the very next verse tells you what he means: "they have no more forever any share in all that is done under the sun" (Ecclesiastes 9:6). He's saying the dead have no more stake in earthly affairs, no more participation in the life happening around us. That's true, and it's what he means.

But here's what the same book says three chapters later:

"The dust returns to the earth as it was, and the spirit returns to God who gave it." — Ecclesiastes 12:7

The body goes to dust. The ruach (רוּחַ, H7307, "spirit/breath of life") returns to God. Qohelet himself gives us both sides of death: the earthly side (no more participation in the world), and the Godward side (the spirit returns to its maker). These aren't in conflict — they're describing two different aspects of the same event.

The same distinction appears in several psalms and in Isaiah 38:18, where people in crisis say "the dead cannot praise you." Those are petition texts — the speaker is essentially saying "if I die, I can't join the congregation to praise you, so please save me." They're making a claim about earthly worship, not about whether the dead are conscious.

So when Paul says "to be absent from the body is to be present with the Lord" (2 Corinthians 5:8), he's not contradicting Ecclesiastes. He's answering a question the Preacher wasn't asking.

Read the full study on the intermediate state