Indeterminism

:"Non-determinism redirects here. For similar articles, see Indeterminacy"Indeterminism is the philosophical belief contradictory to determinism: that there are events which do not correspond with determinism (and therefore are uncaused in some sense).

For instance:
#No event is caused at all
#Some events are not caused at all
#Some events are partially caused
#All events are partially caused.

Science

At one time, it was assumed in the physical sciences that if the behavior observed in a system cannot be predicted, the problem is due to lack of fine-grained information, so that a sufficiently detailed investigation would eventually result in a deterministic theory ("If you knew exactly all the forces acting on the dice, you would be able to predict which number comes up"). However, the advent of quantum mechanics removed the underpinning from that approach, with the claim that (at least according to the Copenhagen interpretation) the most basic constituents of matter behave indeterministically, in accordance with such properties as the uncertainty principle. Quantum indeterminism was controversial on its introduction, with Einstein among the opposition, but gradually gained ground. Experiments confirmed the correctness of quantum mechanics, with a test of the Bell's theorem by Alain Aspect being particularly important because it showed that determinism and locality cannot both be true. Bohmian quantum mechanics remains the main attempt to preserve determinism (albeit at the expense of locality).

Types of cause

Causes are often distinguished into two types: Necessary and sufficient. Necessary causes:

If "x" is a necessary cause of "y"; then the presence of "y" necessarily implies that "x" preceded it. The presence of "x", however, does not imply that "y" will occur.

Sufficient causes:

If "x" is a sufficient cause of "y", then the presence of "x" necessarily implies the presence of "y". However, another cause "z" may alternatively cause "y". Thus the presence of "y" does not imply the presence of "x".

As Daniel Dennett points out in Freedom Evolves, it is possible for everything to have a necessary cause, even while indeterminism holds and the future is open, because a necessary cause does not lead to a single inevitable effect. Thus "everything (does not) have a cause" is not a clear statement of (in)determinism.

Free will

One of the important philosophical implications of determinsim is that, according to incompatibilists, it undermines many versions of free will. Correspondingly, believers in free willoften appeal to physical indeterminism. (See compatibilism for a third option.)

See also

* Aleatoric music
* Causality (philosophy)
* Causality (physics)
* Determinism
* Libertarianism (metaphysics)
* Quantum indeterminacy
* sumbebekos
* dialetheia
* Stochastic

External links

* [http://plato.stanford.edu/entries/incompatibilism-theories/ Incompatibilist (Nondeterministic) Theories of Free Will] from the Stanfor Encyclopedia of Philosophy]
* [http://www.philosophyprofessor.com/philosophies/indeterminism.php indeterminism] from the Philosophy Professor