I was sitting in my recliner when I was struck by a thought. That sometimes happens. Is the reason that plate tectonics exist is because we have the moon? It's conceded by most that the moon's construction was the crash of a proto-planet into Earth. It's contents are principally the same as the remaining crust of Earth. Since this collision tore off so much of Earth's crust, is this why we have plate movement? Essentially the Earth's crust was debulked and lessening the energy requirements to allow movement. Would internal convection processes be sufficient to provide that movement with the added cladding? Would retained heat eventually cause cataclysmic changes due to the added insulation? Other questions derive from this. Would the Earth be Venus-like if this had not taken place? Would an enormous atmosphere exist? Are plate tectonics a principle driver to evolution? To Life and intelligence itself? It shadows arguments concerning the moon's tidal influences on these emergences. If this is a valid, testable theory, I claim it. It may also explain why ETIs have not communicated with us. The sheer chance shearing of the bulk of our crust into an orbiting body has to be a minimal. Crustal thinning gives us access to metal. A principal means for technological advancement within our human paradigm. If this concept has been worked on previously, please inform me. I'd like to read up on it. Thanks.