Of all the sciences, physics has been seen as the key to understanding everything. As Feynman said, “physics is the fundamental science.” But in this article, one of the world’s leading physicists, George F. R. Ellis, who collaborated with Stephen Hawking in work on spacetime’s geometry, argues that much of reality extends far beyond physics. Both complex objects like biological organisms and abstract entities like the rules of chess influence the world in ways that cannot be predicted by studying their simple physical constituents. Science, Ellis insists, is far richer than any single framework can ever capture.

1. Abstract Causation

A remarkable feature of the world is the existence of abstract causation – the way that non-physical entities can cause physical effects via the workings of the human mind, or by the functioning of digital computers we create. The reality of abstract causation shows that physics has limits: there are some things physics cannot explain. Consider the rules of chess. They control the physical movement of chess pieces on chess boards throughout the world. But they are not physical things. They are not made of wood or stone or steel, and they don’t involve electrical or magnetic forces acting on the chess pieces. So how is this control possible?