Naturalism is the word of the day. It is the “ism” that most philosophers embrace (at least in English-speaking climes). Wearers of the badge are a wildly diverse bunch. This is because there are quite different ways of being a naturalist and of conceiving of the naturalistic project. Some naturalists take a special interest in our everyday or folk commitments. For them, the interesting philosophical project is to determine how much, if any, of what we ordinarily think about various subject matters (e.g., mentality, morality, aesthetics) is compatible with our best scientific understanding of what exists. To decide this, special methods have been created for (1) perspicuously representing our folk commitments and (2) examining if these outstrip the commitments of a certain scientific understanding of what nature comprises. By these lights the naturalist’s philosophical task is to determine if the folk are committed to something beyond what is posited by a certain scientific worldview. This naturalistic program, known as the Canberra Plan, relies on a framework devised by its principal architect, Lewis (1970, 1972)—a framework that has been extended by his followers, most prominently Jackson (1998).