In part 1 I argued that we don't have any of the "controversial" type of free will - the type of free will that requires your future be "open" to other possibilities before you act. That is, the philosophical view called libertarianism (not the same as the political view) is wrong.
This is relatively uncontroversial among philosophers; this survey of philosophy professors suggests about 86% agree that libertarianism is wrong. (A small majority of professional philosophers believe we have the kind of free will that's compatible with being completely determined to do what we do - the kind a deterministic robot would have if the robot had genuine wants. Again whether that really counts as "free" will isn't much of an issue, in my book.)
Life without free will isn't so bad
But libertarian free will (which I'll just call "free will" from here on out) is the kind of free will almost all of us thought we had before we really looked at the issue. And the discovery that we aren't free in this sense can be very upsetting. A comment on my part 1 post by 
If it were true that we do not freely make choices nothing we think or do would be of any significance whatsoever. Even deciding to believe that determinism is true would be meaningless! Therefore, since free will is a necessary condition of meaningfulness in life, it seems best to assume we have it. If we do not then life is meaningless and who cares?
Well, if it's true that we have no free will, and you care about important truths even when they're sad, then that is reason to care. And obviously just because some conclusion is sad is no reason to think it's false. It's sad for me to conclude (based on induction from past experience) that this post will not earn more than $2 on Steemit. But the fact that conclusion is sad to me doesn't mean, by itself, that my conclusion is false. (It might be false for other reasons - and I can always hope it will earn more than $2, even if I don't actually believe it will!)
But is this conclusion so sad? Would life really be "meaningless", as
This woud be a shocking discovery, of course. But would you now feel that life is meaningless? For example, would you be totally indifferent if people said "so, since you're only a robot following a sophisticated program, now we're just going to permanently turn you off"? Or would you be like "well actually, I was really looking forward to that concert tonight"? Remember, everything still feels the same as before. Even if your future is never open and you are just following a deterministic path, that path is complicated and unknown to you. You can still be pleasantly (and unpleasantly) surprised at all the twists and turns your life takes. And meanwhile, ice cream still tastes good, even if it's "just" your programming telling you so, and telling you to go get some after the concert. So why kill your (robot) self, and deprive yourself of that (robot) life?
I think we all are robots like that - just made out of meat instead of metal. And maybe our neural chips have random elements too, so we're not even in principle totally predictable. But random coinflips don't actually make us free, as we discussed in part 1.
Why it really matters that we don't have that kind of free will
Well, okay, so fun is still fun, and life is still worth living, even if you're that robot. But here's a deeper worry you might have: as such a robot, nothing you do is really to your credit, because it's all just the result of whatever programming (nature and nurture) you happened to get. If Jane wins the Nobel Prize for Physics, it was because she was born with the right genetic predispositions (smarts, drive, and such), and then had the right teachers, and worked on just the right problem at just the right time - and at the end of the day, really it was all just a matter of luck.
And on the flip side, if Jane ends up losing every job she ever had and living on welfare, then that's not ultimately her fault, either - there are always reasons she loses all these jobs, and the reasons for those reasons and so on are ultimately out of her control. (Or else it was genuinely random factors - but again, that's not her fault.)
"What if she's just-plain lazy?" you ask. Well, as usual, we can ask: what caused Jane to be lazy? If it was in her genes, that's hardly her fault. If her parents and/or mentors and/or peers taught her on average that it's not worth it to work hard, that's not her fault either. ("But she picked her peers!" - Okay, why did she pick those peers over better ones? See where this is going?) Even if she became lazy because she read this post and misunderstood its implications, deciding that "nothing matters so I may as well give up" - well that's not really her fault either, because again we just repeat the "why": why did she misunderstand my post? Did she not have good enough teachers, or was she just not born with this kind of reasoning ability? Whatever the answer is, we repeat until we see that ultimately it was just a matter of bad luck that she lost all her jobs.
I think it's true that nothing is ultimately to our credit or ultimately our fault. We have no true moral responsibility, as Galen Strawson puts it. This has serious implications for (at least) two major policy questions: criminal justice, and redistribution of wealth.
Criminal justice without free will
My students always ask at this point: since nothing is ever anyone's fault, does this mean we should scrap the criminal justice system? Should we never punish anyone, and let anyone do whatever they want?
No. Punishment can still be justified, on this view - but only when it brings net good consequences. To see what I mean, imagine Jane commits crimes that are clearly not her fault (even if you believe in free will); for example, suppose that she sleepwalks and stabs people while asleep, not at all aware of what she's doing. Well, it's not really her fault - so should we let her keep stabbing people? No. We should take her knives away. We should maybe contain her so that she can't be around other people. We should try to get her treatment and cure her of this condition. Even if the treatment is a little unpleasant and Jane doens't want it, society is justified in making her take the treatment if it's the best way to stop her from stabbing more people.
To force Jane to do something she doesn't want is a kind of punishment. This suggests we can justifiably punish Jane even when it's "not her fault" if there are net benefits to it, such as preventing future such crimes.
Those of us who think there is no free will think all criminal punishment should be like that. One such person was the 1920s lawyer Clarence Darrow. He was most famous for the Scopes "monkey trial", but he also famously defended thrill killers Leopold and Loeb from the death penalty. He really believed that even those thrill killers - kids who committed murder just because they thought they were smart and wanted to get away with it - were not really deep down at fault. They obviously had some twisted background that made them so deeply psychologically sick, Darrow reasoned. If Darrow had his way they would have been treated like hospital patients with a dread disease, because they were the unfortunate victims of a lot of bad luck to make them the monsters they became. And again, Darrow really believed this - he wasn't just cynically trying to get his defendants off the hook. Similar sentiments are in his address to the prisoners of the Cook County Jail.
If Darrow and I are right, this means the criminal justice system should never cause people to suffer just because they deserve it for their crimes; there should be no retribution, as philosophers call it. Instead, punishment should be designed primarily to "treat" the criminals of the conditions that caused them to commit the crime in the first place - whether the "sickness" is desperate poverty, lack of any marketable skills, a hopeless outlook, a psychological illness, or just bad anger management. Causing people to suffer just for having such rotten luck is like condemning them to jail for getting pneumonia - as chapter 10 and following of Samuel Butler's classic satire Erewhon suggests.
Wealth redistribution without free will
The same can be said for reward as for punishment. It's okay to reward people for good things they do, but again only if it's for the net best to do so, never because they deserve it for what they did.
Now think about how many people defend against redistributing wealth from the rich to the poor - it's not fair, the claim often goes, that the rich work so hard for their money and then have it taken away. The rich deserve to have wealth as a result of their hard work, and the poor deserve to suffer for failing to contribute. But if you don't believe in (libertarian) free will, no one deserves anything in this sense; the rich were just lucky, and the poor unlucky. The desert argument evaporates. This is obvious in cases like where the rich inherited their wealth, or the poor are oppressed systematically and prevented from holding employment. But it's even true where the rich came up from nowhere (they were lucky to have the right drive, mentors, etc. to become rich) and the poor fell from privilege (they must have still had some unfortunate disadvantage to make them poor).
So does this mean wealth must be distributed perfectly equally in order to be just? No, that is a straw man. It can be to everyone's benefit that there are incentives to be economically productive. Suppose we have two pies to divide up: one is much bigger, but divided into uneven pieces; the smaller one is cut into exactly equal pieces. If the smallest piece of the big pie is still larger than the even pieces of the small pie, we should all prefer the big pie. Because economic inequalities can be to the benefit of all this way, they are fair. But the inequalities should only be in place to the extent that they maximize this minimum share.
This is one way to get to the liberalism of political philosopher John Rawls. Rawls's is the most popular political philosophy among professional philosophers, and I think for good reason ... But I hope to discuss that more in a future "why I gave up libertarianism" post (and then I will mean the political view, not the free will view).
Meanwhile I hope you see why I think this very abstract philosophical problem is at the heart of some of the most crucial "real-world" political issues we face.