 You’re performing an amazing trick right now: you’re in two places at once. How do you manage to be down there, near the floor, and yet also be a metre or two up in the air? Well, it’s not so very amazing: your feet are down there on the floor, and your head is up in the air. Having spatial parts enables you to be in several different places, and to have different properties in different places: you’re cold down there on the tiled floor, and also warm up there by the heater, because your feet are cold and your head is warm. Moreover, having parts could let you be in the same place as someone else: if you shared a hand with a conjoined (‘Siamese’) twin, then you could both wear the same glove without jostling for space.