There are many arguments and reasons that support either stance on the free will v determinism argument, but i believe i may have a theory that can tie up all loose ends.
I beleive in determinism in the sence that everything you do is pre determined. The actions you take are not from your own accord but actually from a set of needs that need to satisfied at that exact point in time when you make a decision. For example, if i have two needs in life and nothing else, one being money and the other being food. As i become hungry my need for hunger outweighs my need for money so i decide to take a break from working and eat some food, i eat and satisfy my need, my need decreases for food and money outweighs my need for food. I then leave the restaurant and go back to work.
I consciously had the decisions to go and do them things, but only because in my eyes i needed to.
This would also tie in with the fact that i do not beleive in selfishness and selflessness. Because i beleive everyone does what their brain beleives at that split second in time is best for their overall needs.
Now you may argue that i could then go on and consiously become a serial killer ( extreme i know ) , because i am just a horrible person bla bla. But, there would be no need for me to do such a thing because it does not satisfy my needs. So imagine there are numerous parallel universes, i would always have chosen not to kill people because it does not fit my needs. Therefore i have no 'free will'
You can also argue, well if i had no free will then i would just sit on my bum all day, watch loads of films and leave the easy life. But this would never happen because my needs are not; need to watch films, need to relax every minute of the day and so forth. My needs range massivly and include things such as self worth, acheivement etc... And that is what influences the things i do.
You can chemically change decisions and change peoples 'free will decisions' by increasing their body's need for nicotine. You have created a need within their body and to satisfy this new need, you need to make decisions to smoke. The only way you can consiously not smoke is to educate the person and make him create needs such as, smell nicer, more accepted in society etc. This then has a chain effect and the costs of not smoking out weigh the costs of smoking. He will gain more from not smoking that he will from smoking. Obviously an outsider can say, just stop smoking, easy enough - because their mind does not have the same needs as the smokers body, so his decision would be to not smoke because it out weighs the benefits of smoking. But this is in contrast to the smoker where he has a need for nicotine.
Therefore these needs must be created from somewhere, and they come from past experiences, these past experiences happened because of their own past experiences and so fourth. Therefore isn't everything pre-determined, but you still make concious decisions to best suit your individual needs.
This is also why i beleieve psycology is so close to physics in the fact that you can predict mass behavious because you can predict the needs if these people as a group.
This also would rise another question about the fact that murderers have no say in the matter that they will commit these crimes, because one of their needs is to murder people. This suits their needs. Otherwise why would they do it? There has ti be a motive and i beleive that is because of a bunch of nature and nuture reasons that have created this need to murder. You may beleive it is wrong, sick and twisted. But this need is by no means un common, because murderers have existed from as far back in history as we can look! Yes numbers of murderers have decreased, but this is because we have introduced greater oppurtunity costs instead of murdering, or higher effects that would do more harm than good, therefore a set amount of would be murderers in a different scenario then choose not to murder.
An argument that people have against determinism is that if they were always going to do this action, then they do nit deserve to go to prison. But they should have to go even if determinism is infact correct, because we have a need for their morals to be re implicated , therefore we feel the need to put them in prison. Therefore they get to prison and undergo an amount of techniques to decrease the incentive to kill, therefore decreasing their need for killing.
Here with this theory you can have a reason for every action one can make, and come to a conclusion that actions are just a way of suiting your personal needs.
But because we are so complex and we do not yet have capacity to understand ourselves we seem to have invented such thing as free will where we have complete say over our bodies actions.
If we could understand our bodies like we understand that a plant grows thin and long to satisfy its need for light and it grows fat and thick to satisfy its need for capturing water then maybe we could predetermine what our next action will be. But ofcourse when you start predicting what the next step will be, you create a burning desire to stop that action from happening therefore never go through with that action. But ofcourse, that was always going to happen, because if this is true then fate is true, and there was a reason and need for figuring out the future. So it is an ever going thing which you could not minipulate, but can see why our brains beleive that we can minipulate our actions.
I would love to hear some thoughts on this, because i do not have the strongest of physics knoledges, i am an AS level student in the UK aged 17, and maybe there are physics theories that prove me wrong but this is the conslusion i have come up with, with the knoledge i know.
So, consider a horse fenced into a pen with an inch and a half of room to move in any direction; quite cramped.
Now consider the horse fenced into a pen with ten feet of room to move in any direction; limited, but there are options.
Finally, consider the horse fenced into a pen with thirty miles of room to move in any direction; weeeeeeee.....
In all of the examples, the horse is not free. Based on the evolution of the horse, it will notice some of the restrictions and perhaps not notice them in other cases. The problem with going on at length as you have about psychology and the feelings of humans about what they want and desire to do next is that they are irrelevant to the freedom of the human. There are so many billions of humans in so many trillions of situations with ten to the power of logarithm a zillion different available options of decision that the primates we are don't think in those ways. There would not be a difference between a universe where we had free choice of ten to the logarithm a zillion options; and a universe where we do one of ten to the logarithm a zillion things without choosing it freely.
Essentially, where is the fence? Demonstrate what freedom I would have that would be lacking in a free universe that does not also exist in an unfree universe.