Libertarianism (metaphysics)

In philosophical debates about free will and determinism, libertarianism is generally held to be the combination of the following beliefs:


 * 1) that free will is incompatible with determinism
 * 2) that human beings do possess free will, and
 * 3) that determinism is false

All libertarians subscribe to the philosophy of incompatibilism which states that an action cannot be both free and physically predetermined in the commonly understood sense. Free actions are ones which could have been different. Traditionally, this has meant that there is no causal chain that necessitated the action prior to the agent freely choosing it; the agent is an originator of causal chains.

However, because of metaphysical worries about this "godlike power", there has arisen the alternative idea that, although the universe is indeterministic, an agent's choice is nevertheless caused by previous events, but those events only assign certain probabilities to its choice (e.g. a 30% chance she will do act A, a 70% chance she will not).

The major objection to libertarianism is that it remains a mystery why an agent makes the choice she does - any explanation of the choice (beyond a probabilistic one) would seem to make it determined. However, according to David Hume, if a choice is not determined then it is simply a random event, which is problematic since such a choice would lack purpose. Attempts to deal with this tend towards dualism, in which mental events, such as choices, are independent of physical causes.

Although quantum mechanics provides some reason for thinking that determinism may indeed be false, Roy C. Weatherford (in the Oxford Companion to Philosophy) echoes Hume on randomness:


 * The random behaviour of atoms certainly does not by itself make for the freedom and moral responsibility asserted by libertarians.

Although not held by the majority of contemporary philosophers, libertarianism is still widely discussed and avidly defended by several leading philosophers on the field, such as Peter van Inwagen, Robert Kane, Timothy O'Connor and Laura Ekstrom. It is still popular among non-academics and is endorsed by some religions as a tenet.