 The constitution theorist has a ready reply to the this objection. Unlike you and the wall, David and Lump share the same parts, and this material coincidence explains how they are able to occupy the same place at the same time (Wiggins 1968). Material coincidence also helps to answer another common complaint. Suppose that Lump weighs 10lbs. David will obviously weigh the same. So why don’t you get a reading of 20lbs. when you place both on the scale? (Lewis 1986, p. 252) Answer: because the two objects share the same weight as a result of sharing the same parts (Zimmerman 1995, p. 89, fn. 57). Here it is important to note that we do not determine the weight of a wall, for example, by summing up the weight of its bricks and its constituent molecules, since that would involve counting some parts more than once. According to the constitution theorist, weighing David and Lump would involve the same kind of double-counting.