 Of course, broad contents also produce a kind of partitioning of possibilities. Any sort of content that determines truth conditions will rule in some possibilities and rule out others. But broad content does not provide the kind of partitioning needed for narrow content. Twin Earth is ruled out by the broad content of my belief that the lakes are full of water, since the lakes on Twin Earth do not contain water. But narrow content was introduced precisely in order to have a kind of content that my Twin and I share, so the narrow content of my thought that the lakes contain water should come out true in a Twin Earth environment centered on my Twin, just as my Twin’s parallel thought comes out true there. A related way to see why Twin Earth is not ruled out by the narrow content of my thought is to notice that I can imagine finding out that all the watery stuff in my actual environment is XYZ. In that case I would not conclude that the lakes do not contain water; instead I would conclude that water is XYZ. So the narrow content of my thought that the lakes contain water does not rule out Twin Earth, even though its broad content does.