So, there is this person called me who is aware of her surroundings, who is able to feel physical sensations and who notices certain of the going-ons in her body. She can even control parts of her body, like the input for motor activity, muscle contractions and so forth - but not everything. She can't control her heartbeat, the bloodflow or the catalyzation processes of enzymes in her stomach.
And yet we have these strange feelings that we control everything, that we are aware of everything that happens in our bodies. But controlling every single task a body has to deal with would be a complete overload of information - if you had to do it consciously.
Obviously we cannot process that much information with our limited brain capacities. But why is there a conscious part at all, making us believe we are in control, even if we are not? Some people might argue that there is something called Free Will which we maintain due to our conscious minds, but I seriously question that there is such a thing.
Not only is there any decision freed from the causal chain that led up to it (and that is what free will ultimately stands for) but it also wouldn't make any sense (in evolutionary terms that is), not to mention that it is based on nothing more than a seemingly comforting idea without any background to prove it.
But the question remains, why do we believe in it, why do we have to think our decision-making is detached from our physical selves, why is it so important to us to be more than we are. Well, it is obvious, why we feel we are important, why we think our existence matters. But the truth is, we are a book that has already been written. Unlike my novel, thanks for asking.
Unfortunately that implies that we are prone to get sick when our genes are damaged and we really can't do much about it but hope that the damage is benign resp. the medical technology is up to date to cure the ailment we have. We want to believe that there is such a thing as a right and a wrong choice to prevent getting sick in the first place, but I guess there is not much we can do. There is a minimal influence.
If I don't walk on the street I can't be run over by a car on that street. But the choice to cross or not to cross it in the first place, is it really ours? Most of the time, the things we want to do derive from physical needs. If there are needs at conflict, none of them surpassing the other, we may have grounds for decision-making. But do we really have a chance to know the difference?
If you really think about, it is ok to be confined by the physical reality.
I try to avoid the term "deterministic universe" because it has been overly used and thereby has lost all meaning to me :)
Being limited also means limited responsibility. If our decisions were free, every little consequence would be something we had to consider before we were able to make a choice. We would be completely responsible. We would never be able to make a decision that way and we would be sitting around, doing nothing for all eternity. Or till we died.
At least, if our decisions aren't free, only the immediate consequences of our doings can be attributed to us. There sure is some wiggle-room in determinism.
I may not really choose what I eat for lunch, some aspects like my blood sugar level may pre-determine what my choices will be and my brain will give me an idea that will appear spontaneous to me, still really isn't, but to my conscious mind it will still feel as if I chose it, because there were some alternatives I denied in the process. And isn't that all we need, the pretense of choice?
Nice, huh? :) If you are interested in this topic I can highly recommend Steven Pinker's book How the Mind Works. Pinker is a cognitive scientist and he not only talks about consciousness, but also general brain phenomena and processes, like how the mind operates, perceives, interacts socially, and experiences emotions. Fascinating, enlightening and sometimes terrifying, but always entertaining :)