 This was certainly the methodology that Lewis accepted. And since he thought that so much of our common sense worldview was compatible with fundamental physics, he had many versions of the location problem to solve. One way to go about this would be to find exactly what the correct scientific theory is, and locate all the relevant properties in that picture. But this method has some shortcomings. For one thing, it might mean having to throw out your metaphysical work whenever the scientific theories change. For another, it means having your metaphysics caught up in debates about the best scientific theories, and about their interpretation. So Lewis took a somewhat different approach.