the extension of that concept in a given world where that world is considered as actual. According to Chalmers, the analysis of a concept’s primary intension “…is an a priori enterprise, as it involves questions about what our concepts would refer to if the actual world had turned out various ways” (1996, 59). In addition to its primary intension, a concept also has a secondary (or “subjunctive”) intension that determines its extension in a given world where that world is considered as counterfactual. The extension of the secondary intension of a rigid concept in a given world—or, more specifically, the secondary intension of a natural kind concept, which is the kind of rigid concept that we’re focusing upon—is determined by first taking the extension of its primary intension in the actual world and then “rigidifying” so that the same extension is picked out by the secondary intension in all worlds (1996, 59). To see this framework at work, let’s apply it to a specific concept: WATER. This concept has a primary intension that picks out whatever happens to be the “watery substance” in each possible world. To put it another way, in determining the extension of the primary intension of WATER, we treat each possible world as though it were the actual world and pick out whatever is “the dominant clear, drinkable liquid in the oceans and lakes” (1996, 57) in that world. Since the primary intension of WATER picks out its extension via relatively superficial features of that extension—and not in virtue of its microphysical essence—the extension of the primary intension of WATER will change from world to world. (In a world where the local “watery substance” was XYZ, for instance, the primary intension of WATER would pick out XYZ.) To express the same idea using some helpful terminology from Chalmers (2003), WATER has a primary intension that is not “epistemically rigid” in that it does not eliminate all the epistemic
fundamental property entails a complex property under Armstrong’s account. To be fair, Chalmers does not assume that phenomenal properties are the result of simply summing together the relevant protophenomenal properties; he allows that phenomenal properties might be determined more “holistically” than this. (See, for instance, Chalmers 1996, 299.) But this is also consistent with Armstrong’s account of complex properties. Recall that Armstrong does not maintain that all complex properties are merely sums of other properties; some complex properties—structural properties—also include relations as constituents. Finally, recall that Armstrong allows that an assemblage of (more fundamental) properties could result in a complex property that conveys causal powers that are less or more than the sum of the powers that would be conveyed by its individual parts considered in isolation of one another. In a similar vein, Chalmers (1996, 154) maintains that an assemblage of protophenomenal properties results in a complex property that has an overall introspectible character that the relevant individual protophenomenal properties, considered in isolation of one another, lack. On the basis of these similarities, I’m going to assume that if they are properties, then phenomenal properties are a type of “Armstrongian” complex property. (Later in this section, I will consider way in which Chalmers could reject this assumption and the potential costs of his doing so.) This means that if phenomenal properties are derived from non-fundamental properties, then they contain other properties—protophenomenal properties—as constituents (or parts). If, in contrast, they are fundamental properties, then they are simple properties that do not contain other properties as constituents (or parts). As a result, the question of whether phenomenal