2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36179This is a summary report of the workshop D2 in GR15. In this workshop rather diverging problems related to quantum gravity and quantum cosmology were discussed. Since it is almost impossible to summarize all these discussions in coherent and integrated expressions, in this report, I give a brief description of the content of each paper in order, with some additional comments on their backgrounds.7 pages, plain LaTeX, to be published in the Proceedings of GR15General Relativity and Quantum CosmologySummary report of the workshop D2: Conceptual Issues, Foundational Questions and Quantum Cosmologytext