Popper: Scientific Determinism Is a Superstition

The Quote

"I hold that scientific determinism is a doctrine which ... is in fact a typical superstition" is Karl Popper's verdict on determinism, from the Preface to The Open Universe: An Argument for Indeterminism (1982). It is the most forceful statement of his lifelong opposition to the belief that the future is predictable in principle.

Context

The Open Universe is the second volume of Popper's Postscript to the Logic of Scientific Discovery, written in the early 1950s and published in 1982. Popper there distinguishes two doctrines. Metaphysical determinism — the claim that the future is fixed no matter what — is untestable. Scientific determinism — the claim that the future can be rationally predicted from a sufficiently precise description of the past together with the laws — is testable, and Popper argues that it fails: classical physics does not entail it (the mathematics allows open systems), and quantum mechanics, read through his propensity interpretation, positively supports indeterminism.

Meaning & Interpretation

Popper's word "superstition" is chosen for effect: determinism, he thinks, is accepted on the authority of an inherited scientific image rather than argued for. His deeper claim is that determinism would be self-defeating. If the future were predictable in principle, then human beings could not genuinely create — new ideas, new theories, new music — because every outcome would already be settled; and science itself, which lives by the emergence of unpredictable novelty, would be impossible. The open universe is the condition of freedom, responsibility, and rational criticism alike.

Legacy

Popper's argument made him a central figure in the philosophy of science's attack on "scientific determinism" and a defender of human freedom against the Laplacean picture. His distinction between scientific and metaphysical determinism is now standard, his critique of prediction in open systems anticipated chaos theory's results, and his defense of an open future continues to inform debates in the philosophy of time and of free will.

Sources

1. Thornton, S. (2021). "Karl Popper." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/popper/
2. Popper, K. (1982). The Open Universe: An Argument for Indeterminism. Routledge.
3. Hoefer, C. (2016). "Causal Determinism." Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/determinism-causal/
4. Popper, K. (1957). The Poverty of Historicism. Routledge & Kegan Paul.