>Of course there are options. They way you're thinking about choice here would render commonplace statements like "I could climb that fence but I don't feel like it" incoherent nonsense, because there wasn't any future in which I would have chosen to do so. That's a strong indication that you're operating with a notion of choice that doesn't line up with the what people generally mean by choice.

Nobody, or at least certainly not me, is going to deny that there is a strong subjective perception of choice in some situations. It seems like you choose whether to go to a party or not, or how much you think you need to study to pass an exam.

It's also obviously true that there are mental states which we are consciously aware of not choosing. People generally don't choose to be sexually attracted or not sexually attracted to someone. They don't choose whether they "click" with someone and become friends. They don't choose whether they prefer to stay in all night watching Netflix or go out to bars.

I think the obvious truth that we generally don't choose our preferences is inherently problematic for the common concept of free will.

>Choices are morally relevant where they give information about the decision maker, and that's where there are a number of options to take under a quite mundane sense of "option". There's a difference between jumping a fence because I wanted to and jumping one at gunpoint regardless of whether the universe is deterministic or not.

That's a weird definition of morally relevant. When I choose to eat vanilla ice cream instead of peanut butter, you're getting information about my preferences. When I choose to murder somebody or refrain from murdering them, you're getting information about my preferences. But most people would say that my ice cream choice isn't morally relevant but my murder choice is. Can you explain what makes you think your definition is sensible?

>A deterministic universe doesn't forbid mental processes from affecting physical processes when mental processes are understood as physical process. But really, you didn't answer my question here. I don't see how even a dualistic universe helps allow free will to exist. What additional factor into a choice does it allow for that wasn't already there?

If it is true that the universe is entirely physically deterministic, then there is no way to distinguish between the processes of the brain which give rise to mental states, including thoughts and choices, and simpler deterministic mechanical systems like internal combustion engines or computers. We do not have the intuition that an internal combustion engine is morally responsible for its actions, or that it is making any choices at all. The same is generally true of computers, at least until we developed computer programs sophisticated enough to trick people's pattern recognition algorithms into interpreting stimulus from a computer as stimulus from a mind. But even where that trick is effective, people are generally at least intellectually aware that everything that's coming out of the computer is predetermined by the motion of electrons and other purely mechanical processes, and by analogy to other machines, that's a pretty convincing argument to most people that chatGPT isn't actually a mind.

>Again, you seem to be saying that for a choice to be free it must be made on the basis of something other than your character, experiences, beliefs, facts of the situation, and random chance. What else needs to influence it for it to be free and how does a nondeterministic universe allow for that when a deterministic one doesn't? So far you've just said that it means mental processes can be nondeterministic but why's that supposed to help?

Most people conceive of free will as existing in the universe where there is a possible counterfactual to a choice. If I choose to eat broccoli instead of cauliflower, the word "choose" only makes sense if there is a possible world in which I ate cauliflower, but based on my mental processes, I influenced the world to become one where I ate broccoli. If there was never a possibility that I would "choose" cauliflower, I didn't make a choice. All that happened was the universe evolved as it was always going to. My mental processes didn't have any effect on the outcome.

In other words, a choice is the ability to actually change the future state of the universe via internal mental processes.

If the universe is entirely physical and deterministic, that's impossible to do. Everything that happens was fundamentally determined by the initial state of the universe and the rules that the universe follows. It is impossible for me to change the universe through choice, precisely because the outcome of my mental processes, which are instantiated in my brain, are entirely physical and predetermined by everything else. There is no "me" to "choose" for the same reasons that we don't think of water choosing to flow downhill or an engine choosing to run.

The only time it is possible for free will to exist is if my mental processes are not entirely predetermined the history of the universe up to the current point. Only that allows me to change the pattern of activation of neurons in my brain and central nervous system and muscles so that I can effectuate my genuine preference. Otherwise my body is a mechanism and everything that happens in the mechanism is fully automatic.

>I think that an nondeterministic universe poses problems for free will, because it means a less strong connection between beliefs/experiences and deliberation, as well as deliberation and action. Of course someone would make the exact same decision every time in the exact same situation: that decision is a reflection of who they were at the time. Why would we ever expect anything else? And to the extent a decision isn't reflective of who they are, it's less morally relevant!

As I said above, if the universe is fully physical and fully deterministic, its evolution in time is predetermined and therefore there is no choice by anyone about anything. People are just like any other composition of matter, and their activities are just like the activities of processes we generally don't consider conscious or mental, like atoms bonding with each other, or water flowing downhill. Only if our actions are somehow not fully determined by the physical universe, but rather can actually be changed by our conscious control of our mental state, can we make choices. You're right that free will then requires our mental processes to be fully determinative of our bodily actions.

>I lean towards what's sometimes called "hard compatibility": that far from being incompatible with determinism, free will in fact might require it.

Free will obviously requires that we, at at least some times and in at least some ways, be able to affect the physical universe through our mental processes, including and especially conscious choices. Otherwise, at best, we would be consciousnesses trapped in our bodies.

But in the sense that people commonly understand it, it also requires that the universe not predetermine our choices. It requires that we make choices of our own volition and not simply because a particular subatomic particle was close to another particular subatomic particle at the attosecond after the Big Bang.