indeterminism

Indeterminism is the view that not all events are determined by prior causes and the laws of nature. It stands in contrast to determinism, which holds that every event is necessitated by preceding conditions. Some use a broader distinction between metaphysical indeterminism (events lacking sufficient causes) and epistemic indeterminism (our knowledge of causes is incomplete).

In philosophy, indeterminism is often discussed in relation to free will and moral responsibility. Libertarian accounts argue that sometimes choices are not determined by prior states, whereas compatibilists maintain freedom can coexist with determinism. Critics warn that indeterminism may not resolve questions about responsibility or agency.

In science, quantum mechanics is frequently cited as embodying indeterminism, with outcomes that are inherently probabilistic rather than certain. By contrast, many classical theories are deterministic, though chaotic systems can exhibit practical unpredictability. Some interpretations of quantum theory, such as many-worlds, dispute the notion of fundamental indeterminacy.

Indeterminism also appears in biology, economics, and other fields through stochastic or probabilistic models that describe random variation, chance events, or incomplete knowledge, rather than deterministic laws alone. The concept continues to inform debates about explanation, prediction, and the nature of scientific laws.