 Another argument is that quasi-dependence cannot account for what came to be known as ‘trumping pre-emption’. Lewis illustrated this idea with an example from Jonathan Schaffer (2000). The troops are disposed to obey all orders from either the Sergeant or the Major. But they give priority to the Major’s orders, due to the Major’s higher rank. Both the Major and the Sergeant order the troops to advance, and they do advance. Intuitively, it is the Major, not the Sergeant, who caused the advance, since the Major’s orders have priority. But the advance does quasi-depend on the Sergeant’s orders, since in a world where the Major doesn’t make an order, the advance does depend on the Sergeant.