Arguments for Determinism and for Freedom

We have one apparently powerful argument for the incompatibility of freedom and determinism (the Consequence Argument in the last lecture).  For the moment let us grant that incompatibility.  Which of the two theses should we believe?  We cannot rationally believe both (although we could rationally believe neither).  To which thesis, if either do the arguments lend the greatest support?
 

1 Determinism and the scientific enterprise

The thesis of determinism is an incredibly bold one.  It claims that every event is caused.   The thesis of indeterminism, the denial of determinism, is thus rather modest.  It claims that not all events are caused.   (Note that the indeterminist does not claim that all events are not caused.  Rather, she claims that not all events are caused:  for indeterminism to be true there just has to be one undetermined event in the universe.)  In order to back up their very bold claim it would seem that determinists require a pretty convincing argument.

Here are two arguments for determinism that often crop up.
 
 

1.1    Determinism as a presupposition of the enterprise of science:

    It is widely held that the enterprise of science is to find out the causal laws: that is, to find out what causes what.  If determinism were not true then some events would not be subject to rational scientific scrutiny.  Scientists would simply have to give up their inquiries if they thought that the universe contained random, inexplicable events which are not subject to causal laThus the thesis of determinism is a presupposition of the enterprise of science, and if we want to pursue the scientific investigation of the world then we have to believe in determinism. ws. 
 

1.2    Determinism supported by the amazing success of science

  The enterprise of science has been tremendously successful in discovering the causal laws of the universe.  While it is by no means the case that we can explain everything that happens by means of these laws, nevertheless we can explain an awful lot more than we could 3,000 years ago, or even 100 years ago.  This success of science in discovering more and more causal laws, and in extending our ability to explain events in terms of their causes, confirms the thesis of determinism.
 
Question:  Do scientists have to believe that every event is subject to causal laws, or only that most events are subject to causal law?
One of the weaknesses of these two arguments is that, while they may have appeared very convincing last century (when the fundamental laws of physics were thought to be deterministic) they look decidedly less convincing today (when the fundamental laws of physics are not generally thought to be deterministic).  Last century the best theories around were Newton's physics and Maxwell's electrodynamics: both explicitly deterministic theories.  According to Newton's theory, for example, the laws of motion together with the precise state of all physical particles in the universe at a particular moment determine the whole future course of all those particles.

A deterministic law involves strict causal connections between events.  At their simplest they have the following form: if an event of type A occurs then it brings about an event of type B.  (A simple example: heating a piece of metal causes it to expand.)  An indeterministic, or probabilistic law, involves tendencies of events to occur.  At their simplest they have the form: if an event of type A occurs then an event of type B has a certain probability of occurring.  (A simple example:  if a particle is generated by a certain process then there is a probability of 1/2 that it will be spin-up and probability 1/2 that it will be spin-down.)  If the physicists are right, and the modern theory of quantum mechanics is correct, then at least some of the fundamental laws are probabilistic.  There is an uncaused, or random, element in the behavior of some items in the universe.

It would follow that (a) scientists do not need to presuppose determinism in their search for laws, for the laws they are searching for may be indeterministic rather than deterministic; and (b) current science actually undermines the thesis of determinism, because the best current theories of physics are not deterministic.  So both arguments turn out to be unsound.
 

Question: Even if there were indeterminism at the micro level (atomic, and subatomic particles) would that guarantee that human actions are not determined?

2 Arguments for freedom

We are going to look at three arguments for the thesis that we are free: the argument from deliberation, the argument from praise and blame, and the argument from introspection.

2.1 The argument from the rationality of deliberation

 

i     Deliberation is required by rationality

Rational people deliberate.  It is one of the hall marks of the rational agent that s/he deliberates about what to do.
 

ii     Deliberation presupposes freedom

In order to deliberate about whether to perform act A or act B one is rationally obliged to suppose that one is free to choose between A and B.
 

iii     Rationality of belief in freedom

If rational people believe in freedom it must be the rational thing to believe.
Since rational people deliberate at least on some occasions, and since rational people who do deliberate believe they are free to choose among the options over which they are deliberating, it follows that rational people believe they are free.  So the thesis of freedom is the rational thing to believe.

This argument is somewhat underwhelming.  It is rather like Pascal's wager in establishing the rationality of believing we are free without directly establishing the thesis itself.  Moreover it seems that the term rationality may be being used in two different senses. The sense in which i is true involves practical rationality - the rationality of acton.  Whereas the sense of rationality we are interested in in the conclusion is cognitive rationality—ßthe rationality of belief.
 

2.2 The argument from responsibility

The second argument has a similar structure to the first.
 

i     Praise and blame can be rational

We are in the habit of praising and blaming people for what they do and on some occasions at least it is rational to do so
 

ii     Praise and blame presuppose responsibility, which in turn presupposes freedom

It would be irrational to praise or blame people unless we thought that they were actually responsible for the things we praise and blame them for.  And to be responsible for what they do they must freely choose what they do.
Combining i and ii here with thesis iii (if rational people believe in freedom it must be the rational thing to believe) from argument one, we get the same conclusion:   the thesis of freedom is the rational thing to believe.

Similar criticisms apply to this argument as apply to argument one.
 

2.3 The argument from introspection

Sometimes we have this overwhelming sense that some things are up to us.  So some things are up to us.

How good an argument is that?  People can be systematically brainwashed into believing all sorts of things which are not true, and they can be adamantly convinced that they are.  We need something more than brute conviction in order to be rational.

Here is what I think is the rational kernel of the argument from introspection.

We seem to be capable of predicting, in a remarkably reliable, which actions are, and which are not, within our power.  I predict that I can raise my arm, and I raise it, thereby establishing the truth of my prediction.  I predict I can walk down the stairs and I do so.  I do this hundreds and hundreds of times each day.  Of course sometimes I make mistakes, but for the most part, certainly concerning everyday actions, I am an astonishingly good predictor of what I can and cannot do.  It is not clear what the mechanism is by which I come to be convinced that something is within my power, but whatever the mechanism is it is extraordinarily reliable.  It is certainly a strange kind of knowledge, and about the best we can do in describing it is to say that we have a "feeling" that some action is up to us.  All I am adding to that is that this "feeling" is usually quite a reliable guide to our powers.  Now, quite often I judge two incompatible actions (say, raising my arm, and not raising my arm) both to be (separately) within my power.  I judge that I can now raise my arm, and also that I can now refrain from raising it.  Given that such judgements of mine are the product of this extraordinarily reliable mechanism, I have very good evidence that they are correct.  And if they are both correct, then I am free — some things are up to me.

The upshot of this survey of standard arguments is this.  We have two weak arguments for the thesis of determinism, two weak arguments for the thesis of freedom and one quite good argument for the thesis that we are free.  If we also accept the argument for incompatibilism it seems that we should now embrace libertarianism: that we are free, and our freedom requires that our actions not be determined.