Determinism is the view that all events occur as a result of prior events and the laws governing reality.
Although determinism does not entail naturalism (the view that there are no extra- or supernatural causes), it is usually defined in terms of natural laws and events.
Determinism should be distinguished from fatalism, which is the view that some future events will occur regardless of what happens between the present and that future time. Determinism is fatalistic, in the sense that the current state of events and the laws of nature entail that certain events will occur rather than others. But it is not identical to fatalism, which holds that these events will occur regardless of other occurrences.
The earliest version of determinism is probably best associated with the views of the atomists, Leucippus (early fifth century BCE) and Democritus (c. 460-c. 370 BCE), although Leucippus seems to allow that, in rare cases, atoms may “swerve” unaccountably. Determinism was popular with Roman stoics and found support in the physics of Sir Isaac Newton. Philosopher Arthur Schopenhauer once said, “A man can do what he wants, but not want what he wants.”
Determinism is significant in the history of thought primarily in its relationship to the “free will problem,” that is, the question of what sort of freedom is required for morally responsible agency. If responsibility demands that agents be free to choose among a variety of options at the moment of decision making, then determinism is incompatible with moral responsibility. And even the sort of indeterministic luck highlighted by Leucippus’s swerving atoms may be incompatible with moral responsibility. However, if responsibility is a matter of internal dispositions toward actions, or “reactive attitudes,” determinism may be compatible with moral responsibility.