I. Experiment and the development of the theory of weak interactions: From Fermi to V-A

Fermi's theory

Toward a universal Fermi interaction; muons and pions

Beat-decay theory following World War II

The discovery of parity nonconservation

The V-A theory of weak interactions and its acceptance

II. Toward a philosophy of experiment

Experimental results

The roles of experiment

Do mutants have to be slain, or do they die of natural causes? The case of atomic -parity-violation experiments.