 In light of these issues, when considering GTR, Brown (2005, ch. 9) focuses entirely on thesis (2), presented in the introduction to this section: no piece of geometrical structure has its ‘chronogeometric significance’ of necessity – that is, no piece of geometrical structure is necessarily surveyed by physical bodies; rather, in order to ascertain whether such is the case, one must pay detailed attention to the dynamics of the matter fields constituting those physical bodies. This, indeed, should already be evident in light of the examples discussed in the previous subsection, such as the Jacobson-Mattingly theory, in which matter does not ‘advert’ to the designated piece of spacetime structure.