Determinism may be broadly defined as the thesis that there is at any instant exactly one physically possible future. The views that spring from this are more complex, however. It often leads to the view that everything is predetermined. But if everything is predetermined, then this means that the determinist must deny the existance of free will. If we believe in biological determinism, the idea that all human action is determined completely by biological instinct, then we must throw away any notion that human beings have control over their own choices. Consequentially, hard determinist are adamant deniers of the existance of free will. Ultimately, determinism should be called mechanicalism, in that it puts forth that human action is just as mechanical as other phenomenon in the natural sciences and that we should therefore apply the exact same methodology to human thought and action.
The determinist position can be shown as absurd very easily because it is a reducto ad absurdum and a performative contradiction. In short, to take determinism as a dogma requires that we believe in pre-destination, that all human action is completely pre-programmed, and hence people have no control over themselves at all. Of course, if people had no control over themselves at all, they would be unable to take any actions at all. So determinism indeed leads us to a reducto ad absurdum. Logic leads us to the conclusion that human behavior is purposeful behavior, that humans use their (limited) rationality to make choices.
It must be noted that the idea that there is only one possible future at all times consistantly must lead to the idea that we can deterministically predict the future. Reality shows us otherwise: that human behavior is expressly not perfectly predictable. If you one willing to defend the idea that we can predict the future, I'd be delighted to have you come up with an arguement that doesn't fall back on mysticism. As I see it, it is impossible for you to make such an arguement without falling back on mysticism.
I reject the "one possibility" theory. For any instant there is a multitude of possible outcomes. In science, we call this probability. Beyond that, human beings, using their minds, have at least a limited power to determine the course of their actions. Since this choice is made by the individual, and every individual is different from one another, it is impossible to predict the future in the way that determinism claims to.
To say that actions are not brought about necessarily and inevitably means they could have been performed differently. One way of thinking about this is to imagine that one can "rewind history". If libertarian free will holds, things will turn out differently. Actions can only occur if they are possible. Libertarian free will requires that there is more than one possible outcome to a given situation.
Determinists sometimes claim that we are not determined by our atoms and molecules so much as by the social and cultural forces on us. While these are no doubt an influence, they cannot add up strict determinism in every case, or we would still be in the caves. Every new idea, social or technological, is something of a rebellion against the old order.
The determinist, if her arguments are applied to herself, cannot claim to have made a rational choice to believe in determinism, because she cannot claim to have made a choice. Without volition, there is no difference between rational discourse and parotting. Her comments carry no more persuasive force than the message on an answering machine.
The determinist, in the course of making their arguements for determinism, must find themselves in a ridiculous absurdity: The idea that you have no choice is negated by your choice to type on your computer as you currently are. To claim that your choice to favor determinism and to write about it here was pre-destined is absurd. You chose to do it. To claim that the only possible outcome was for you to do it is absurd - you could have just as easily chosen to not do it (hence, the free will that you seem to deny having). The problem with your determinism is that you are trying to apply the methods of the natural sciences to the social sciences. This is a fallacy.
Human behavior does not work in the same way that laws of the natural sciences do. While you might be able to claim that the apple will always fall when gravity effects it - this same methodology is hogwash when applied to the human mind and human action. "The mind" is something incapable of truly being measured (indeed, it is intangible, even more intangible than gravity, which can be measured) - and hence, determinism has zero application to it. People's minds react in a variety of ways to something, because people have wills! If people do not have wills, everyone would be the same, as there would be nothing to distinguish them. Obviously, everyone is not the same, because each person possesses individuality, as determined by their own choices.
Deterministic prediction of the future is the field of con artists, not sound social scientists. The mere existance of individuals who disagree with eachother simply negates the entire notion. People's behavior cannot have one single, pre-determined outcome if different people recieve different outcomes for the same behavior (which happens all the time) and different people have different reactions to the same stimuli (which happens all the time). The evidence clearly points us towards the existance of variance. The existance of variance within humans, in turn, negates the entire philosophy of determinism, particularly as applied to the social sciences. So long as Joe is a different person than Jack in any way at all, determinism is simply wrong. Determinism could only even approach being correct if everyone is identical. Since people are not identical, there will always be more than one possible action and outcome.
Why is it that there can be more than one possible action and outcome? Different people CHOOSE to take different actions, and people's perceptions and values that they attach to these actions vary according to their own choices and beliefs, hence we find ourselves once again staring free will in the face. It is a total fallacy to use the methods that describe our instinctual bodily functions (such as breathing and the like) to try to map out the mind, which functions in a different way. Thoughts and actions do not function in the same way that instinctual things such as your heart beating does. Indeed, your heart beat is controlled biologically, independantly of your will. But it is simply nonsensical to apply this to thoughts and actions, to claim that all thoughts and actions are pre-determined biologically.
A note on religiousity and free will: While western religions tend to support the concept of free will, the concept is not an explicitly religious one. To the contrary, in secular philosophy, these notions go back to Aristotle and Plato, who in turn got them from people even longer before that. It would therefore be disingenous to imply that the only way for me to believe in free will is from a religious or dogmatic perspective. To the contrary, free will is a self-evident thing that can easily be discovered employing basic logic. Indeed, all one has to do is open one's eyes and live life to see proof of it.
Unfortunately, if we take determinism seriously, all notions of human rationality dissapears, and humans are denigrated to mere savages, completely bound by instinct. To take determinism seriously, we must believe that humans function exactly like a lion or elaphant in every way; that is, governmed completely by instinct. But this simply is not true. Humans are precisely defined by the ability to supress their instincts. The only way to suppress instinct is through *tadda* free will.
Determinism must lead the determinist to treat regaurd humans in the same way as a computer. For example, a determinist recently made this arguement:
"My chess program, when faced with a bad position makes a move and loses its queen. Could it have not lost the queen? Sure...if it had only moved the knight to d7 instead of its bishop to a8. Could it have really, under the circumstances, have made any other decision than it did?"
The proper reply is as follows: Using a computer, a chess program, as an example of human behavior is beyond the pale. Yes, the computer could not have magically developed a will of its own and made another decision. This has no bearing on human behavior. It's a computer. Computers are not humans; I.E. they have no real conciousness or choice. Humans do. As a human, indeed, you could have made another chess move by choosing to think about it longer (with your free will).
Trying to draw a conclusions about how humans operate by using how a machine operates is simply a fallacy. Who made this machine anyway? Humans. Can the machine make other machines by choosing to? No, because it is not a concious being. Humans are, hence they choose to make computers. The machine can only make another machine if a human programs it to. The human, on the contrary, can choose to make a machine without some "prime mover" programming the human to. The computer possesses no such qualities of the human. They function in completely different ways. The computer will always give you the same result if you make it do a math problem. Humans are prone to error and will give you different results. The computer has no opinions. Humans do. The computer has no emotions. Humans do. So yes, the dychotomy is absurd by all standards of reason.
It would also be absurd to apply the methodology that we use for studying the universe and planertary bodies to human thoughts and actions. The existance of sentience makes it absurd. The universe does not think. It does not choose. To apply this same model to humans is absurd. Humans think thoughts and take actions. The universe does not, it simply functions without conciousness.
All human beings have experience of being a self-determining being, we are all aware of the free choices we have made. We all have experience of deliberating, of weighing factors which could influence our decisions and this often takes a long time. without free-will, our practices of morally praising some and condemning others has no rational basis.
We do not hold people morally responsible if they could not have acted otherwise than they did (if they were under external duress, or suffer from an internal compulsion such as kleptomania). However, determinism makes everyone unable to do other than as they did, so it follows that no-one is ever morally responsible, and the prisons should be emptied. This demonstrates how the denial of free will means that noone can possibly be responsible for their own actions; people can avoid incrimination and responsibility by hiding behind determinism.
The two best logical arguements for the existance of free will and self-ownership have been made by Murray Rothbard and Hans Herman Hoppe.
It has been argued by Austrian School economist Hans-Hermann Hoppe that self-ownership is axiomatic. His reasoning is that a person contradicts himself when he argues against self-ownership. The person making this argument is caught in a "performative contradiction" because, in choosing to use persuasion instead of force to have others agree that they are not sovereign over themselves, that person implicitly grants that those who he is trying to persuade have a right to disagree. If they have a right to disagree, then they have legitimate authority over themselves.
In The Ethics of Liberty, Murray Rothbard argues that 100 percent self-ownership is the only principle compatible with a moral code that applies to every person - a "universal ethic" - and that it is a natural law by being what is naturally best for man. He says if a every person does not entitled to full self-ownership, then there are only two alternatives: "(1) the 'communist' one of Universal and Equal Other-ownership, or (2) Partial Ownership of One Group by Another - a system of rule by one class over another." He says that it is not possible for alternative (2) to be a univeral ethic but only a partial ethic which says that one class of people do not have the right of self-ownership but another class does. This, therefore, is incompatible with what is being sought - a moral code applicable to every person - instead of a code applicable to some and not to others, as if some individuals are humans and some are not. In the case of alternative (1), every individual would own equal parts of every other individual so that no one is self-owned. Rothbard acknowledges that this would be a universal ethic, but, he argues, it is "Utopian and impossible impossible for everyone to keep continual tabs on everyone else, and thereby to exercise his equal share of partial ownership over every other man." He says the system would break down, resulting in a ruling class who specializes in keeping tabs over other individuals. Since this would grant a ruling class ownership rights over its subjects, it would again be logically incompatible with a universal ethic. Even if a collectivist Utopia of everyone having equal ownership of everyone else could be sustained, he argues, individuals would not be able to do anything without prior approval by everyone in society. Since this would be impossible in a large society, no one would be able to do anything and the human race would perish. Therefore, the collectivist alternative universal ethic where every individual would own an equal portion of every other individual violates the natural "law of what is best for man and his life on earth." He says that if a person exercises ownership over another person, that is, uses aggression against him rather than leaving him to do as he wills, "this violates his nature."