Pierre Curie claimed that a symmetry of a cause must be found in the produced effects. This paper shows why this principle works in Curie’s example of the electrostatics of central fields, but fails in many others. The failure of Curie’s claim is then shown to be of special empirical interest, in that this failure underpins the experimental discovery of parity violation and of CP violation in the twentieth century.

Curie’s Principle says that any symmetry property of a cause must be found in its effect. In this article, I consider Curie’s Principle from the point of view of graphical causal models, and demonstrate that, under one definition of a symmetry transformation, the causal modeling framework does not require anything like Curie’s Principle to be true. On another definition of a symmetry transformation, the graphical causal modeling formalism does imply a version of Curie’s Principle. These results yield a better understanding (...) of the logical landscape with respect to the relationship between Curie’s Principle and graphical causal modeling. (shrink)

Is there more that one "Curie's principle"? How far are different formulations legitimate? What are the aspects that make it so scientifically fruitful, independently of how it is formulated? The paper is devoted to exploring these questions. We start with illustrating Curie's original 1894 article and his focus. Then, we consider the way that the discussion of the principle took shape from early commentators to its modern form. We say why we think that the modern focus on the inter-state version (...) of the principle loses sight of some of the most interesting significant applications of the principle. Finally, we address criticism of the principle put forward by Norton and purported counterexamples due to Roberts. (shrink)