B1: Modality in Physics and in Metaphysics

这个项目是基于这样一个论点，即模态在科学中占有一席之地，特别是在物理学中：模态结论的归纳推理并不仅仅出现在形而上学中，而且也是物理学实践的一部分。物理学中至少有四种类型的模态归纳推理：从实验结果推断出某一种理论不可能是真的（类型1），而相对于给定的标准理论的替代理论被判断为在物理上同样可能，其定律是偶然的（类型2）。另外两种类型的模态推理涉及特定结构的基本性或非基本性，因为它们存在于一个理论的全部或仅部分模型中（类型3），以及作为理论统一的结果（类型4）。从归纳形而上学的角度看，形而上学推论的基本前提必须与经验事实和低级理论相容，而推论的结论不能与物理学内部推论所建立的结论相矛盾。两个案例研究将提供应用归纳形而上学的例子，通过反映物理中模态推理所施加的限制。第一个案例研究涉及温伯格的自旋2-量子引力方法对黎曼时空的本体论地位的挑战（参见类型4）。第二个案例研究的目标是尊重归纳形而上学的最小约束的自然法则理论，通过肯定它们的偶然性（参见类型2），但比阿姆斯特朗对法则的描述更好地掌握了因果必然性。

This project is based on the thesis that modality has a place in science, and in particular, in physics: Inductive inferences to modal conclusions do not exclusively appear in metaphysics, but are also part of the practices of physics. There are at least four types of modal inductive inferences within physics: From experimental outcomes it is inferred that theories of a certain kind cannot possibly be true (Type 1), whereas alternative theories with respect to a given standard theory are judged to be equally physically possible and their laws to be contingent (Type 2). Two further types of modal inferences concern the fundamentality or non-fundamentality of particular structures as following from their presence in all or only some models of a theory (Type 3), and as a result of theory unification (Type 4). From the perspective of Inductive Metaphysics, the basic premises of metaphysical inferences must be compatible with empirical facts and lower level theories, while their conclusions must not contradict conclusions established by inferences within physics. Two case studies shall provide examples of applied Inductive Metaphysics by means of reflecting the constraints imposed by modal inferences within physics. The first case study concerns the challenge by Weinberg's Spin 2-approach to Quantum Gravity to the ontological status of Riemannian space-time (cf. Type 4). The second case study aims at a theory of laws of nature respecting the minimal constraints for Inductive Metaphysics by affirming their contingency (cf. Type 2), but providing a better grip on causal necessitation than Armstrong's account of laws.