 Yablo’s philosophical conceivability (CON),  involves imagining a world that one takes to verify some proposition \(p\). Note that when imagining a world, we don’t need to specify all the details in the world in imagination. The imagining provides prima facie evidence for the possibility of \(p\) because it involves what Yablo calls an “appearance of possibility” (i.e., it seems as if \(p\) is possible, given the imagined world). “[T]o imagine an \(X\) is thereby to enjoy the appearance that an \(X\) could exist” (1993: 30).