Samuel Schindler (Aarhus University)
Einstein famously distinguished between constructive and principle theories. He believed only the former to be explanatory. Lange has recently argued that principle theories explain, too, by virtue of putting necessary constraints on the laws of physics. In this paper, I want to draw attention to the fact that constructive theories also offer explanations in terms of necessities: they represent contingent regularities as necessities. I call this feature 'structural necessitation' and the understanding afforded by it 'how-necessarily' understanding. In contrast to the necessities of Lange's explanations by constraint, structural necessitation can be brought about by causal mechanisms.
