Determinism
The thesis that every event is the necessary outcome of prior causes.
In practice
Sentencing assumes an offender could have acted otherwise. A hard determinist treats that assumption as false and argues for deterrence and rehabilitation; a compatibilist keeps the assumption by redefining what 'could have' requires.
The common mistake
Confusing determinism with fatalism. Fatalism says the outcome arrives whatever you do; determinism says your actions are themselves causes, fully part of the chain that produces the outcome.
Determinism is the claim that every event follows necessarily from prior causes and the laws governing them. Given the state of the world at one moment, only one future is possible.
The classical statement
The clearest formulation is Pierre-Simon Laplace's, in 1814. An intelligence knowing the position and momentum of every particle, and able to analyze the data, would see past and future with equal clarity. Nothing would be uncertain in principle; uncertainty would be a fact about the observer.
The argument with free will
If determinism holds, the state of the world before your birth plus the laws of nature entail everything you will ever do. Three positions divide the response:
- Hard determinism accepts determinism and concludes that free will is an illusion, along with the desert-based part of moral responsibility.
- Libertarianism holds that we do act freely and concludes that determinism is false of human action.
- Compatibilism holds that both are true, because freedom means acting from your own desires and reasons without external compulsion, which determinism does not disturb. Hume argued this directly: an action with no cause at all would be random, and randomness is no better a foundation for responsibility than necessity.
Physics and the question
Quantum mechanics is often taken to have settled the matter by introducing genuine chance. It complicates determinism without rescuing free will, since an action produced by an indeterminate event is not thereby under the agent's control. The philosophical problem survives the physics largely intact, which is why compatibilism remains the most widely held position among specialists.
The question connects to causation, to fate as its older and more personal cousin, and to the Stoic practice of amor fati, which asks what attitude to take toward a world you did not author.
Concept web
Open the full webQuestions
What is determinism?
The thesis that every event is the necessary result of prior causes operating under natural laws, so that given the state of the world at any moment, only one future is possible.
Does determinism mean free will is impossible?
Only on some views. Hard determinists say yes. Compatibilists argue that freedom means acting from your own reasons without compulsion, which is consistent with those reasons having causes.
Does quantum physics disprove determinism?
It challenges determinism at the level of fundamental physics by introducing genuine probability. It does not by itself support free will, since an action caused by a random event is not thereby under the agent's control.