Actually, this is where I'm genuinely confused. I can see how a theist would believe that they are ultimately in charge of their own existence, but I cannot understand how an atheist would make this claim. If their is/are no god(s), and everything is created by natural processes, then everything a person does would be a result of nature, nurture, or some combination. To state it even more basically, everything any form of life does is dictated by thermodynamics, kinetics, and statistics. Which of these can you control? It would seem that the exact opposite would be concluded, that a person has no control over their existence. I have read papers that state that free will originates from evolution, but if you read what is really being said, it is not free will as most people perceive it, but rather that your choices are programmed into you based on evolution. Basically, the conclusion seems to be that the ability to independently direct your life is a myth. I don't mean this as an attack, I'm just trying to understand.
Frankly, the idea of freewill as most people think of it is impossible.
Mark Twain's "What is Man" has a section that does a good job at illustrating this IMO.
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Y.M. Yes. "Everything has its limit--iron ore cannot be educated into gold."
O.M. There are gold men, and tin men, and copper men, and leaden mean, and steel men, and so on--and each has the limitations of his nature, his heredities, his training, and his environment. You can build engines out of each of these metals, and they will all perform, but you must not require the weak ones to do equal work with the strong ones. In each case, to get the best results, you must free the metal from its obstructing prejudicial ones by education--smelting, refining, and so forth.
Y.M. You have arrived at man, now?
O.M. Yes. Man the machine--man the impersonal engine. Whatsoever a man is, is due to his MAKE, and to the INFLUENCES brought to bear upon it by his heredities, his habitat, his associations. He is moved, directed, COMMANDED, by EXTERIOR influences--SOLELY. He ORIGINATES nothing, not even a thought.
Y.M. Oh, come! Where did I get my opinion that this which you are talking is all foolishness?
O.M. It is a quite natural opinion--indeed an inevitable opinion--but YOU did not create the materials out of which it is formed. They are odds and ends of thoughts, impressions, feelings, gathered unconsciously from a thousand books, a thousand conversations, and from streams of thought and feeling which have flowed down into your heart and brain out of the hearts and brains of centuries of ancestors. PERSONALLY you did not create even the smallest microscopic fragment of the materials out of which your opinion is made; and personally you cannot claim even the slender merit of PUTTING THE BORROWED MATERIALS TOGETHER. That was done AUTOMATICALLY--by your mental machinery, in strict accordance with the law of that machinery's construction. And you not only did not make that machinery yourself, but you have NOT EVEN ANY COMMAND OVER IT.
Y.M. This is too much. You think I could have formed no opinion but that one?
O.M. Spontaneously? No. And YOU DID NOT FORM THAT ONE; your machinery did it for you--automatically and instantly, without reflection or the need of it.
Y.M. Suppose I had reflected? How then?
O.M. Suppose you try?
Y.M. (AFTER A QUARTER OF AN HOUR.) I have reflected.
O.M. You mean you have tried to change your opinion--as an experiment?
Y.M. Yes.
O.M. With success?
Y.M. No. It remains the same; it is impossible to change it.
O.M. I am sorry, but you see, yourself, that your mind is merely a machine, nothing more. You have no command over it, it has no command over itself--it is worked SOLELY FROM THE OUTSIDE. That is the law of its make; it is the law of all machines.
Y.M. Can't I EVER change one of these automatic opinions?
O.M. No. You can't yourself, but EXTERIOR INFLUENCES can do it.
Y.M. And exterior ones ONLY?
O.M. Yes--exterior ones only.
Y.M. That position is untenable--I may say ludicrously untenable.
O.M. What makes you think so?
Y.M. I don't merely think it, I know it. Suppose I resolve to enter upon a course of thought, and study, and reading, with the deliberate purpose of changing that opinion; and suppose I succeed. THAT is not the work of an exterior impulse, the whole of it is mine and personal; for I originated the project.
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The conscious you as you think of yourself is just a mechanism of your brain. Your decisions and opinions are all dictated by your brain as well.