A Word of Clarification
My argument is that the irreconcilability of determinism and so called indeterminism is an illusion based on a confusion of categories.
I do not violate any laws of nature when I raise my hand and snap my fingers. The mechanics of the motions of bones, muscles and nerves in my arm and hand and the neurochemical changes in my brain can be precisely described by a biologist.
If you ask him why I snapped my fingers, he will look at you dumbfounded, and announce that, as a biologist, his discipline is confined to empirical statements about empirical reality, that is, things open to the senses.
Likewise, if you ask a lawyer or a father confessor why I snapped my fingers — let us assume for the sake of argument that this snapping was sinful or illegal — they will answer in terms of free will and malice aforethought. They will answer in terms of ends and means, that is, offer as statement about what I meant to achieve and how I mean to achieve it by the act of snapping.
All discussion of ends and means is non-empirical. The empirical facts have little or nothing to do with such discussions. They are two different ways of describing two difference faces of reality, the seen and the unseen.
Asking how physical determinism and moral choice can coexist, in effect, asking how can the inside of a cup exist if the outside exists.
Myself, I do not see how one is possible, or imaginable, without the other.
If there is no cause and effect in the material world, there is no decision-making, no morality, no human action in the mental world. And without action in the mental world, categorizing sense impressions into categories, such as causation versus accident, is likewise impossible.
Think of eyesight as a line going from point A to point B. Point A is and must be physical, an empirical event, an object, something seen. If not physical, it is not something one can see with the eye.
Point B is not the optic nerve, not the visual cortex — these are still movements along the line from A to B — but your personal perception, which is an image, that is, a symbol, you hold in your mind. You are a you because you have viewpoint.
Perception is symbolic. Symbols have neither mass, shape, volume, currency, candlepower, or any other material property.
Again, human action is a motion along a similar line from B to A, when an impulse to act arises from the will, is confirmed by the reason (or allowed by its negligence) and is transformed into muscular and physical action, such as words or deeds.
Any argument that says body rules mind, because physical objects cause perceptions, is equally valid as an argument that says mind rules body, because impulses to action cause physical actions.
In the specific case mentioned, if the motion of the gunhand at the moment of killing can be described in terms of an endless chain of physical causes leading back to the Big Bang, then that description will not say whether or not the killing was in self defense, or performed in the heat of passion or by malice aforethought.
All the descriptions of all the atomic motions in the universe, including the descriptions of brain actions in motion, will not tell you the truth about the situation, which is whether or not the shooter is guilty of a crime.
I suspect you are confusing the case where someone against my will thrusts my finger against a trigger and pushes, and a case where I decide to commit a killing for reasons that seem good to me. The description of the muscle motions of my finger do not include a description of why I did what I did.
Also, descriptions cannot “cause” anything, any more than chance can “cause” anything. That is just a way of speaking. A physical description of how my body moves does not suddenly turn me into a helpless puppet.
What you are describing, within the medical limits of what is possible for me at my strength and agility, and if my nerve and muscles are working, is how I chose to move my body.
If, as a strict empiricist, you are required to leave out of your description the real cause why I did what I did, snapped a finger or pulled a trigger, that is a limitation of empiricism.