Structural realists claim that structure is preserved across instances of radical theory change, and that this preservation provides an argument in favor of realism about structure. In this paper, I use the shift from Newtonian gravity to Einstein’s general relativity as a case study for structural preservation, and I demonstrate that two prominent views of structural preservation fail to provide a solid basis for realism about structure. The case study demonstrates that (i) structural realists must be epistemically precise about the concrete structure that is being preserved, and (ii) they must provide a metaphysical account of how structure is preserved through re-interpretation in light of a new theory. Regarding (i), I describe a means of epistemic access to the unobservable that I call “thick detection” of structure, which isolates the structure that will be preserved. Regarding (ii), I argue that thickly detectable structure is preserved across theory change through a process of extracting the old structure from the new structure, much like what has been done with geometrized versions of Newtonian gravity. With these two responses in hand, the structural realist can adequately account for the preservation of structure and can provide a strong argument in favor of structural realism.

结构现实主义者声称，结构在激进理论变革的情况下得以保留，并且这种保留提供了支持关于结构的现实主义的论据。在本文中，我以从牛顿引力到爱因斯坦广义相对论的转变作为结构保存的案例研究，并证明结构保存的两种重要观点未能为结构的现实主义提供坚实的基础。该案例研究表明，（i）结构现实主义者必须对所保存的具体结构在认识上是精确的，（ii）他们必须通过根据新理论重新解释来提供如何保存结构的形而上学解释。关于（i），我描述了一种对不可观察的认知访问的方法，我称之为结构的“厚检测”，它隔离了将被保留的结构。关于（ii），我认为通过从新结构中提取旧结构的过程，在理论变化中保留了厚重的可检测结构，就像牛顿引力的几何版本所做的那样。有了这两种回应，结构现实主义者就可以充分解释结构的保存，并可以提供支持结构现实主义的强有力的论据。