Jia, Ding2023-08-212023-08-212023-08-212023-08-16http://hdl.handle.net/10012/19734A physical theory of everything is supposed to tell us: (1) The dynamical laws for matter and gravity; (2) The boundary condition of the universe; (3) The relation between the theory and experience. I present a personal assessment for different possibilities in addressing these tasks, which leads to the following picture for the most likely case. The dynamical laws for matter and gravity are captured by a joint matter-gravity path integral. The boundary condition is such that all configurations are summed over indifferently. The interior condition selects for individual experiences and nothing else. A human life is characterized by a sequence of experiences. Probabilistic predictions for each individual experience can be found in path integrals of the above form, but no collective account for joint experiences can be given. Individual experiences are related by their enabling conditions, which encode memories. Comprehension of objects are constructions, derived from regularities and repetitive patterns among the experiences.enDoctoral Thesis