The dissertation investigates some relevant metaphysical issues arising in the context of spacetime theories. In particular, the inquiry focuses on general relativity and canonical quantum gravity. A formal definition of spacetime theory is proposed and, against this framework, an analysis of the notions of general covariance, symmetry and background independence is performed. It is argued that many conceptual issues in general relativity and canonical quantum gravity derive from putting excessive emphasis on general covariance as an ontological prin-ciple. An original metaphysical position grounded in scientific essential- ism and causal realism (weak essentialism) is developed and defended. It is argued that, in the context of general relativity, weak essentialism supports spacetime substantivalism. It is also shown that weak essentialism escapes arguments from metaphysical underdetermination by positing a particular kind of causation, dubbed geometric. The proposed interpretive framework is then applied to Bohmian mechanics, pointing out that weak essentialism nicely fits into this theory. In the end, a possible Bohmian implementation of loop quantum gravity is considered, and such a Bohmian approach is interpreted in a geometric causal fashion. Under this interpretation, Bohmian loop quantum gravity straightforwardly commits us to an ontology of elementary extensions of space whose evolution is described by a non-local law. The causal mechanism underlying this evolution clarifies many conceptual issues related to the emergence of classical spacetime from the quantum regime. Although there is as yet no fully worked out physical theory of quantum gravity, it is argued that the proposed approach sets up a standard that proposals for a serious ontology in this field should meet.
The paper shows how the Bohmian approach to quantum physics can be applied to develop a clear and coherent ontology of non-pertur-bative quantum gravity. We suggest retaining discrete objects as the primitive ontology also when it comes to a quantum theory of space-time and therefore focus on loop quantum gravity. We conceive atoms of space, represented in terms of nodes linked by edges in a graph, as the primitive ontology of the theory and show how a non-local law in which a universal and stationary wave-function figures can provide an order of configurations of such atoms of space such that the classical space-time of general relativity is approximated. Although there is as yet no fully worked out physical theory of quantum gravity, we regard the Bohmian approach as setting up a standard that proposals for a serious ontology in this field should meet and as opening up a route for fruitful physical and mathematical investigations.
The Transreflective Dimensional Model (MTD) is reformulated as a speculative pre-spatiotemporal relational framework rather than as a completed theory of quantum gravity or a direct unification of quantum mechanics and general relativity. The central hypothesis is that observable physical distinctions need not correspond to primitive distinctions in the fundamental ontology. The fundamental domain, denoted by
X, is assumed to admit multiple relational manifestations without any manifestation possessing a privileged ontological status as an “original.” Observable properties, subsystem decomposition, and potentially spacetime itself are treated as emergent structures associated with context-dependent manifestations of
X. The paper introduces a minimal set of postulates and investigates their mathematical consequences. A quotient construction is shown to remain compatible with a classical Boolean theory, demonstrating that pre-spatiotemporality, relational emergence, and transreflective equivalence alone are insufficient to recover quantum mechanics. A groupoid-based realization is developed as a candidate mathematical representation of reversible transreflective relations, while a non-globality condition is examined as a route to contextual nonclassicality. The analysis establishes several no-go results: the present MTD postulates do not uniquely derive quantum mechanics, the Born rule, purification, general relativity, or the Standard Model. MTD 2.0 therefore does not claim a Theory of Everything. It is presented as a mathematically explicit foundational research framework and as a starting point for investigating whether transreflective principles can generate independently testable physical structure.