1. Determinism, simple indeterminism, and fatalism

• Deterministic systems: In our everyday lives, we typically deal with things (systems) whose behavior is completely predictible, at least in principle. For example, if my car is in working order (that is, the battery is charged, the wires connected, etc.) and I turn the ignition key, then the car will start. Now, one might say, suppose that it does not start, a common enough experience. Then, I assume that the car was not in working erder, that is, that the battery was not charged, and/or the wires not connected, and/or... In other words, I assume (correctly) that if the car is in working order and the ignition key turned (that is, the car is in a certain initial state state), then there will be one and only one outcome: it will start. In other words, I assume that the car is a deterministic system. We can make this more precise.

  Suppose that S is in initial state IC. Then, if there is a set of laws DL ruling the temporal evolution of S that, given IC, always determine the same outcome, S is a deterministic system. In other words, if given IC and DL there is only one possible outcome, then S is a deterministic system. Note that in a deterministic system, every state depends on previous ones.
  

• A simple indeterministic system is one whose temporal evolution includes random jumps. For example, some believe that quantum systems, upon measurement, randomly acquire the values of the properties being measured. So, if I were to measure the momentum of a quantum particle in a given physical state P and obtain the value of X, and then measure the momentum of another particle in the very same physical state P, I could obtain (amazingly) a result different from X. As far as we know, macroscopic systems such as the brain, when in contact with other macroscopic systems, do not display random features.
• Fatalism: For Determinism, events depend on and are determined by previous IC and  DL. Hence, don't confuse Determinism with Fatalism, which is the view that the past and the present have no effect on the fated future.  Consider the following argument during an impending hurricane: "tonight either I'll die or not.  If I die, then taking precautions is useless.  If I don't die, taking precautions is superfluous.  Hence, taking precautions is useless or superfluous."  This argument, which is formally valid (but is it sound?), embodies Fatalism.  If Fatalism is true, then what you do or don't do has no effect whatsoever on fated events.  Note also that one could hold that Fatalism is true only with respect to certain events, although it's hard to see why only these events should be fated.

2. Importance of issue of free will for ethics: praise and blame involve  responsibility, which involves free will.
Example: punishment as retribution presupposes responsibility, and hence free will.

There are two basic position on the issue of free will and determinsm: incompatibilism and compatibilism.

3. Incompatibilism: this is the view that free will and human determinism are incompatible. In other words, I cannot both be a determinstic system and have free will.

Here is the standard argument for this view:

1.  Free will entails the ability to do otherwise.
2.  The ability to do otherwise is incompatible with determinism because given IC and DL the outcome cannot be changed (it cannot be otherwise..
3.  Hence, determinism and free will are incompatible.
   

Criticism of (1) and (2):

Objection to (1):
"I could have done otherwise" is irrelevant because of cases of over-determination.   For example, I want an apple and so I pick one; however I also have an implant that makes me want apples when I want fruit (that is, I'm over-determined).  Still, since my wish did not come from the implant, one might say that I picked the apple freely.  Nevertheless, I could not have done otherwise because of the implant.

Possible reply: Insist that in cases of over-determination, there is only the illusion of free will. In reality, one has no free will unless one really had the power to do otherwise.

Objection to (2):
"I could have done otherwise" must be understood as elliptic for "I would have done otherwise if I had so chosen," which is how it is (perhaps) normally understood. But this sense of "I could have done otherwise" is compatible with human determinism.
Possible reply: if human determinism true, then I could not have willed differently.

4. Incompatibilism splits in two opposite camps: some incompatibilists, the hard determinists, claim that we are deterministic systems and that consequently we do not have free will. Others, the libertarians or free willists, claim that we have free will, and consequently we are not deterministic systems.

Evidence in favor of the view that we are deterministic systems:

• When we interact with people, we behave as if they were deterministic systems.
• The brain is a complex midsized electrochemical system. Typically, such systems are deterministic.
• Libet's experiments: voluntary movement is precededby about 1/2 second by brain activity detectable with a simple EEG. Hence an experimenter can tell that the movement will occur about 1/2 second before it actually occurs. However, the earliest time the subject reports forming a conscious intention of moving is about 200 milliseconds before the motion.

NOTES:

• Lack of free will seems to lead to the denial of moral responsibility.  Hence, no retribution is morally justifiable.  Incapacitation, deterrence and amelioration are the only morally justifiable components of punishment left.
• A deterministic system needn't be like a zombie in that it can have flexibility, intelligence, knowledge, and wisdom.

Evidence in favor of free willism:

First argument:

1. Introspection shows that my choices are a manifestation of free will.
2. Introspection is reliable
3. Hence, I have free will

Problem: there's little evidence that introspection is always reliable, as post-hypnotic suggestion shows.  More generally, even assuming that I'm unaware of being determined, it doesn't follow that I'm aware of not being determined.

Second argument:

1. We have a capacity to choose in cases of indifference of equilibrium.
2. But choices are possible only if we have free will.
3. Hence, we have free will
   Problems:
   • the only evidence we can choose in a state of equilibrium is introspection, which is not reliable.
   • even if we can choose in a state of equilibrium, the mechanism of choice may be determined (e.g. a subroutine which is called up when we are stuck).  All the argument shows is that if I am a deterministic system, I'm a rather flexible one.

NOTE: free willists do not adopt indeterminism but agent causation. My free actions are not uncaused (random, as in quantum mechanics), nor are they caused by my previous mental states. Instead, they are caused by me, the agent. That is, I (the person) cause the changes in the brain eventually resulting in my actions.

Problem: What is this mysterious entity, the person, that can cause changes in the brain without being caused itself to do so? Note that it cannot be the sum total of one's mental states.

5. Many philosophers reject both hard detrminism and free willism because they reject the idea that free will and determinism are incompatible. These are the supporters of Compatibilism or Soft Determinism.

Here is an argument for compatibilism:

1. free will is acting as one decides, without external impediments or constraints.

NOTE: hence, the real issue is not whether actions are caused, but whether they are caused or prevented by external forces, impediments, or constraints.
2. an action (or a choice) can be free of external impediments or constraints and yet be totally determined.
3. hence human determinism and free will are compatible.

Criticism of (1): Absence of external impediments or constraints is not enough to guarantee freedom of the will.
NOTE: It's crucial to understand that Compatibilists are as much determinists as Hard  Determinists: they don't disagree on whether we are determined (they think we are), but on whether this precludes having freedom of the will.