The Free-Will Postulate in Quantum Mechanics

TL;DR

This paper redefines the concept of free will in quantum mechanics, proposing an 'unconstrained initial state' condition that aligns with determinism and alters traditional causality and locality interpretations.

Contribution

It introduces a new formulation of free will, compatible with deterministic theories, impacting how causality and locality are understood in quantum models.

Findings

The 'unconstrained initial state' condition aligns with determinism.

Imposing this condition restricts free will to setting measurement parameters.

It suggests a different perspective on causality and locality in quantum mechanics.

Abstract

The so-called "free will axiom" is an essential ingredient in many discussions concerning hidden variables in quantum mechanics. In this paper we argue that "free will" can be defined in different ways. The definition usually employed is clearly invalid in strictly deterministic theories. A different, more precise formulation is proposed here, defining a condition that may well be a more suitable one to impose on theoretical constructions and models. Our axiom, to be referred to as the `unconstrained initial state' condition, has consequences similar to "free will", but does not clash with determinism, and appears to lead to different conclusions concerning causality and locality in quantum mechanics. Models proposed earlier by this author fall in this category. Imposing our `unconstrained initial state' condition on a deterministic theory underlying Quantum Mechanics, appears to lead to a restricted free-will condition in the quantum system: an observer has the free will to modify the setting of a measuring device, but has no control over the phase of its wave function. The dismissal of the usual "free will" concept does not have any consequences for our views and interpretations of human activities in daily life, and the way our minds function, but it requires a more careful discussion on what, in practice, free will actually amounts to.