Certain recent philosophical theories offer the prospect that zombies are possible. These theories argue that experiential contents, or qualia, are nonphysical properties. The arguments are based on the conceivability of alternate worlds in which physical laws and properties remain the same, but in which qualia either differ or are absent altogether. This article maintains that qualia are, on the contrary, physical properties in the world. It is shown how, under the burden of the a posteriori identification of qualia with physical properties, a reasoned choice can be made between the two types of theories which ultimately favors materialism and rejects zombies.