Abstract Uses a historical approach to explore the extent to which quantum theory mandates indeterminism. Drawing on important examples in the history of physics, it discusses explicitly the crucial distinction – often overlooked in the philosophical literature – between indeterminacy of physical quantities and causal indeterminism. It pursues at a more sophisticated level, issues raised in Ch. 2 concerning determinism and indeterminism in modern science. It concludes that quantum indeterminacy is an objective feature of the world, but that the jury is still out regarding quantum indeterminism.
``Branching space-time'' is a simple blend of relativity and indeterminism. Postulates and definitions rigorously describe the ``causal order'' relation between possible point events. The key postulate is a version of ``everything has a causal origin''; key defined terms include ``history'' and ``choice point.'' Some elementary but helpful facts are proved. Application is made to the status of causal contemporaries of indeterministic events, to how ``splitting'' of histories happens, to indeterminism without choice, and to Einstein-Podolsky-Rosen distant correlations.