2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54886This is a talk presented at the conference ``Historical and Philosophical Reflections on the Foundations of Quantum Field Theory,'' at Boston University, March 1996. It will be published in the proceedings of this conference.17 pages, LaTeX, no macros needed, no figuresHigh Energy Physics - TheoryCondensed MatterGeneral Relativity and Quantum CosmologyHigh Energy Physics - Phenomenologytext