I'm going to call free will a sensation of imagined control of future events based on an incompletely calculated prediction of how current conditions will determine them.
Our big forebrains were honed and sculpted by eons of natural selection to model the current status of ourselves and our environment. Those brains better able to predict the future from perceived regularities in these current, constantly updated, models and those better suited to guiding near future actions based on those models survived and, more importantly, replicated better. The sense of self and the illusion of free agency able to affect future events has been positively selected for and highly preserved. Self preservation is easier to accomplish if one recognizes there is a self to preserve. Intentional actions are only possible if there is a self with motivation to intend. Free will is the subjective experience of this motivation.
Justice takes place in a substantially more complex milieu. It involves not only a self, but the entire community of persons interacting in a society. It isn't possible to have a system of ethics with only one individual isolated from its environment. If we were able to perfectly predict the emergent patterns stemming from the unimaginably complicated interactions building from a statistically significant number of QM events we would be able to answer the question of whether will is free or determined (subject to whether QM is actually random or only appears so.) The existence of that question depends entirely on our capacity to measure and model. Unfortunately, that capacity is not very great.
Alex, I'll take compatibilism and consequentialist justice for $2000.
Our big forebrains were honed and sculpted by eons of natural selection to model the current status of ourselves and our environment. Those brains better able to predict the future from perceived regularities in these current, constantly updated, models and those better suited to guiding near future actions based on those models survived and, more importantly, replicated better. The sense of self and the illusion of free agency able to affect future events has been positively selected for and highly preserved. Self preservation is easier to accomplish if one recognizes there is a self to preserve. Intentional actions are only possible if there is a self with motivation to intend. Free will is the subjective experience of this motivation.
Justice takes place in a substantially more complex milieu. It involves not only a self, but the entire community of persons interacting in a society. It isn't possible to have a system of ethics with only one individual isolated from its environment. If we were able to perfectly predict the emergent patterns stemming from the unimaginably complicated interactions building from a statistically significant number of QM events we would be able to answer the question of whether will is free or determined (subject to whether QM is actually random or only appears so.) The existence of that question depends entirely on our capacity to measure and model. Unfortunately, that capacity is not very great.
Alex, I'll take compatibilism and consequentialist justice for $2000.
So how, exactly, does God know that She's NOT a brain in a vat? 
