One case Thomas Nagel presents about free will is shown using a cake and peach example. He starts it off by saying that you are in a cafeteria line and choose to take a piece of chocolate cake instead of a peach.
Before you made up your mind on which food item you were going to grab, it was completely open whether you would take the fruit or the dessert. It was then only your choice that decided which it would be and you could have chosen a peach even if everything else had been exactly the same as it was up until that point in your life when in fact you chose the cake.
Because of this, nothing would have had to be different for you to have chosen the peach, besides simply your choice. Because of this, it was not determined in advance and determinism is therefore false.
Nagel also adds that some things in this world are actually determined in advance, such as the sun rising tomorrow at a specific hour and that is not an open possibility, but your choice regarding which food item to eat was not inevitable or determined in advance. You chose the cake simply because you wanted the cake more than you wanted a peach and “there were no processes or forces at work before you made your choice that made it inevitable that you would choose the chocolate cake”.
The desire for cake was purely stronger than the negative consequence of gaining weight. If determinism was true, I would then feel trapped knowing every action I make was determined before I was born and there is absolutely nothing I could do about it. That would mean every person is a puppet on a string that is not really living life but acting as if in a movie by a predetermined script. This would subsequently unveil the issue about punishment and reward in life.
If someone commits a wrong action, why should they be punished if they were basically living out their predetermined role? If that was true, they had no more power over their wrong decision than rain does for falling from the sky. The same goes for reward. If an athlete has a really exceptional play, why should I reward that person with praise if that action was predetermined to happen all along? I shouldn’t, which makes everything in life almost worthless.
There would be no reason to work for anything or try new things if you were always on a track towards one ultimate ending in life with no other possibilities. That is why I agree with Nagel’s view on free will being true over the argument of determinism. Determinism has very good arguments as well, but the mere possibility that all of the choices and situations I haven’t yet encountered are already predestined is so strange and takes away the enjoyment and mystery of life.