I was listening to Neil deGrasse Tyson on Star Talk the other day, and he was answering a question about orbits. But he added that it's not entirely true that, for instance, the earth orbits the sun, because the earth doesn't orbit the sun's center. Rather, both the earth and the sun both orbit their common center of gravity, which happens to be really close to the center of the sun, but not exactly. He also said that this isn't entirely true either, and I forget what exactly his reason was, but for some reason this reminded me of Peirce's essay defining a new list of categories. His categories begin with Being, which is the unity itself, whenever you predicate anything of anything else. His list ends with Substance, which he refers to as the What Is, which is the basic empirical content of the world that can't be summed up in any sort of concept scheme. Between Being and Substance are several different grades of concept, each one becoming more sophisticated, in the same way that the concept of orbit was slowly becoming more sophisticated.
So when I think of a statement such as that the earth orbits the sun, I generally think of the simplest version, unless I think of it some more, and then I think of the more sophisticated version. Maybe, if I think about it some more, I can grow even more sophisticated, by noting the gravitational influence of more and more bodies on the orbit of the earth and the sun, whether the strong influence of Jupiter in our solar system, to the extremely slight and insignificant, yet certain, gravitational influence of distant galaxies. Ultimately, I might conclude that all mass orbits all other mass, but by now I'm using the term "orbit" in an extremely sophisticated but difficult way. I question if even concept of "orbit" should even apply here.
So is it valid to be a skeptic of concepts here and say that all of our concepts are really false in a similar way? Is there any way of measuring how close to "substance" a concept is, or is this an idiosyncratic Peircean invention?