One of the worst defenses for free will is that determinism may be true, but if the common person finds out, all hell will break loose. No one will then be morally responsible, or can be held to that standard, once the “cover is blown.” Among many arguments against this, is that just because one gains the knowledge, it does not follow that he will choose to commit crimes, etc.
Because the defense is basically, “If they find out the truth, they will use their “free will” to escape responsibility, commit crimes and bad acts, loaf in bed all day, quit going to work, or doing ANYTHING.” This is inane, since finding out the truth doesn’t “free” one from determinism. You’d do the same thing you are determined to do- the knowledge wouldn’t change anything- although it MIGHT be determined that certain people will, after gaining this knowledge, commit crimes, it doesn’t follow that the person did so of their own “free will.”
Because you can’t have both. If the knowledge precedes new action, that was inevitable, given all the factors, the gained knowledge being one of the factors contributing to the outcome.
Just like if you could read the future and see who your spouse will be, and if you don’t like it, you can’t just avoid the marriage. It’s inevitable that you will, somehow, even against your preference and all effort to avoid it. Otherwise, the future you saw was not the truth- not real. If you can change the future from what it otherwise would be, you could never predict it with certainty (and that’s the case now, although if we had complete knowledge of the present we would be able to see what the inevitable future is).
In fact, you could never predict any outcome of any of your own actions either. If libertarian free will, which amounts to randomness, is the case, any choice you make, the ensuing result would be up for grabs, every time. All the things we take for granted, such as relying on automobiles, airplanes, tools, etc. are not random happenstance – if decisions are to mean anything, they must be based on some degree of predictability. The law of gravity will not suddenly cease to exist- we can be quite reliably certain that if we drop a ball, it will fall.
In other words, if determinism is true, and people “taught” it widely, and people actually believed it, there would be no mass inertia, or mass hysteria. Life would go on as usual, as intended. Like me, and all types of determinists, we just do what the day brings us. We get out of bed somehow, react to our environment, learn, remain law-abiding, get to work, etc., all without “free will,” and us knowing it doesn’t make us suddenly OBTAIN free will so that we can willy nilly commit crimes knowing we can’t be held responsible!
Just briefly it is quite possible that none of us can actually avoid living under the illusion of “free will,” even if we intellectually do not believe it to be true. It may be a state of nature that we are “programmed” to think we are in control, we make choices as free agents, and we could have done otherwise. There may be very good reasons for us to live in this illusion- I won’t get into.