Determinism
Determinism is the philosophical doctrine which claims that every physical event, including human cognition and action, is causally determined by an unbroken chain of prior occurrences. The principal consequences of this doctrine are that free will is an illusion, and that the outcomes of all future events have already been determined. Determinism is associated with the ideas of Materialism and Causality. The long list of philosophers dealing with this issue includes David Hume, Thomas Hobbes, Immanuel Kant, and, more recently, John Searle.
Determinism is a broad concept subject to various interpretations. For example, determinism and free will are often, but not always, viewed as mutually exclusive. The idea that they might be compatible (or that free will even requires determinism) is called Compatibilism. If incompatible with determinism, free will is only the illusion of the human feeling of agency, and persons may not have an independent effect on the universe.
The doctrine of a determinined universe has been articulated in both Western and non-Western religion, philosophy, and literature. In the West, determinism is often associated with Newtonian physics, which argues that the physical matter of the universe operates according to a set of fixed, knowable laws. The "billiard ball" hypothesis, a product of Newtonian physics, argues that because the initial conditions of the universe have already been established, it is theoretically possible, with complete knowledge of physical matter and the laws governing that matter, to predict the time and place of every event that will ever occur. In this sense, the universe operates in the same fashion as the rolling balls on a billiard table, moving and striking each other in predictable ways to produce only slightly-less predictable results.
Some critics of determinism argue that if people are incapable of independent choice there can be no basis for morality. Others, more recently, have interpreted the developing field of quantum mechanics as being consistent with the argument that some basic events may be truly random and non-deterministic.
Determinists have responded to the first critique by distinguishing between normative and objective claims, arguing that statements of fact can and should be made independently of their consequences. Thus, even if determinism is inconsistent with the idea of a moral universe, that does not necessarily invalidate its conclusions.
With respect to the second critique, there are two main counter-arguments:
1) Quantum mechanics has been misinterpreted, and the idea of "randomness" has wrongly been interpreted to mean the occurrence of something entirely uncaused by prior events. The "random" movements of sub-atomic particles are random in the sense that no human measurement can account for or predict them. They are not random in the sense that they have no prior cause. These events occur according to probability and may have a yet-unknown cause.
2) If non-determistic interpretations of quantum mechanics may be correct, and uncaused events occur, these events are not the products of human cognition. The actions of a human would be determined by a random quantum mechanism, not an independent will.
Intrinsic to the free will vs. determinism debate is the issue of first causes. Either the entirety of space-time came into existence at some point without any prior cause, in which case the determinist argument fails, or else space-time has always existed, leaving both sides to contemplate the problem of infinity.
See also