Niels Bohr: Philosopher in Action

An intellectual biography of Niels Bohr (Joint work with Anja Skaar Jacobsen)

Philosophical Lessons of the Theory of Relativity

Relativity theory might seem less philosophically provocative than quantum physics, and easier to read literally, i.e., as telling us how things are (in themselves). In fact, one might say that there is something of a consensus among philosophers about how to read relativity theory. But that has not always been the case — and I’m convinced that if there is a consensus now, then it rests on some indefensible presuppositions.

Metatheory and Theoretical Equivalence

It’s possible to make up some precise (mathematically rigorous) versions of familiar concepts. For example, in the 19th century, mathematicians came up with definitions for concepts such as a function being continuous, or of a collection being infinite. In the 20th century, mathematical logicians continued this practice by proposing definitions for concepts such as provability, truth (in a structure), and equivalence (of theories).

But some philosophers complain about this methodology, saying that the notion of equivalence is not "formal", or even more extremely, that it's a bad idea to talk about theories in the first place – rather than about more solid things such as facts. I remain convinced that meta-theoretic concepts (i.e., concepts about our representations and how they relate to the world) are useful, and that explication of such concepts is a valuable practice. But it’s important to clarify what we attend to achieve via this methodology.