  Free will is sometimes summarised in the philosophical literature as the
subjective impression felt by an individual that he or she is the ultimate
source or cause of his or her own choices. The two most common arguments for
denying the existence of free will come from philosophy and neuroscience. The
first argument is the Consequence Argument. The second asserts that our
decisions are first made by the brain and only then become conscious to the
subject, taking away the control of the decision. The purpose of these two
arguments is to demonstrate that an individual cannot be the source or primary
cause of his or her choices. It is shown in this work that the concepts of
primary cause and primary source are not adequate to state a solid
characterisation of free will. A new formulation of this property is proposed
in which it is seen as a three-stage decision-making process implemented by an
individual to escape his or her own real or supposed alienation. This
decision-making process is represented in the form of a computer model called
the PSU (Predictability - Suspension - Unpredictability) model. The
compatibility of this new formulation of free will with the feeling it provides
and the analysis of various situations are then discussed.
