According to modern physics, nothing is as solid as it seems. Things that seem so turn out to be tiny points of energy, in precarious equilibrium, giving our rough senses only an impression of solidity … This truth in physics holds also in the fields of politics, law, and economics. There are plenty of things that seems solid enough, like ancient empires or modern armies or (in the economic field) money. But on careful inspection these, too, turn out to be points of energy, in temporary equilibrium, in the beliefs and feelings of individuals. When these change, the seeming solid dissolves into its constituent points, which then reassemble in new forms—with an equally deceptive appearance of corporeality.
– Alexander Murray, ‘Excommunication & Conscience in the Middle Ages’