this amounts to is much less certain. According to David Hume, the
question of the nature of free will is "the most contentious question
of metaphysics." If this is correct, then figuring out what free will
is will be no small task indeed. Minimally, to say that an agent has
free will is to say that the agent has the capacity to choose his or
her course of action. But animals seem to satisfy this criterion, and
we typically think that only persons, and not animals, have free will.
Let us then understand free will as the capacity unique to persons
that allows them to control their actions. It is controversial whether
this minimal understanding of what it means to have a free will
actually requires an agent to have a specific faculty of will, whether
the term "free will" is simply shorthand for other features of
persons, and whether there really is such a thing as free will at all.
This article considers why we should care about free will and how
freedom of will relates to freedom of action. It canvasses a number of
the dominant accounts of what the will is, and then explores the
persistent question of the relationship between free will and causal
determinism, articulating a number of different positions one might
take on the issue. For example, does determinism imply that there is
no free will, as the incompatibilists argue, or does it allow for free
will, as the compatibilists argue? This article explores several
influential arguments that have been given in favor of these two
dominant positions on the relationship between free will and causal
determinism. Finally, there is a brief examination of how free will
relates to theological determinism and logical determinism.
1. Free Will, Free Action and Moral Responsibility
Why should we even care whether or not agents have free will? Probably
the best reason for caring is that free will is closely related to two
other important philosophical issues: freedom of action and moral
responsibility. However, despite the close connection between these
concepts, it is important not to conflate them.
We most often think that an agent's free actions are those actions
that she does as a result of exercising her free will. Consider a
woman, Allison, who is contemplating a paradigmatic free action, such
as whether or not to walk her dog. Allison might say to herself, "I
know I should walk the dog—he needs the exercise. And while I don't
really want to walk him since it is cold outside, I think overall the
best decision to make is that I should take him for a walk." Thus, we
see that one reason we care about free will is that it seems necessary
for free action—Allison must first decide, or choose, to walk the dog
before she actually takes him outside for his walk. If we assume that
human actions are those actions that result from the rational
capacities of humans, we then see that the possibility of free action
depends on the possibility of free will: to say that an agent acted
freely is minimally to say that the agent was successful in carrying
out a free volition or choice.
Various philosophers have offered just such an account of freedom.
Thomas Hobbes suggested that freedom consists in there being no
external impediments to an agent doing what he wants to do: "A free
agent is he that can do as he will, and forbear as he will, and that
liberty is the absence of external impediments." In An Enquiry
Concerning Human Understanding, David Hume thought that free will (or
"liberty," to use his term) is simply the "power of acting or of not
acting, according to the determination of the will: that is, if we
choose to remain at rest, we may; if we choose to move, we also may.…
This hypothetical liberty is universally allowed to belong to everyone
who is not a prisoner and in chains." This suggests that freedom is
simply the ability to select a course of action, and an agent is free
if he is not being prevented by some external obstacle from completing
that course of action. Thus, Hobbes and Hume would hold that Allison
is free to walk her dog so long as nothing prevents her from carrying
out her decision to walk her dog, and she is free not to walk her dog
so long as nothing would compel her to walk her dog if she would
decide not to.
However, one might still believe this approach fails to make an
important distinction between these two related, but conceptually
distinct, kinds of freedom: freedom of will versus freedom of action.
This distinction is motivated by the apparent fact that agents can
possess free will without also having freedom of action. Suppose that
before Allison made the choice to walk the dog, she was taking a nap.
And while Allison slept, there was a blizzard that moved through the
area. The wind has drifted the snow up against the front of her house
so that it is impossible for Allison to get out her front door and
walk her dog even if she wanted to. So here we have a case involving
free will, because Allison has chosen to take the dog for a walk, but
not involving free action, because Allison is not able to take her dog
for a walk.
Whether or not one can have freedom of action without free will
depends on one's view of what free will is. Also, the truth of causal
determinism would not entail that agents lack the freedom to do what
they want to do. An agent could do what she wants to do, even if she
is causally determined to do that action. Thus, both Hobbes and Hume
are rightly characterized as compatibilists.
Even if there is a distinction between freedom of will and freedom of
action, it appears that free will is necessary for the performance of
free actions. If Allison is brainwashed during her nap to want to walk
her dog, then even if no external impediment prevents her from
carrying through with this decision, we would say that her taking the
dog for a walk is not a free action. Presumably, the reason why it
would not be a free action is because, in the case of brainwashing,
Allison's decision does not arise from her free will. Thus, it looks
like free will might be a necessary condition for free action, even if
the two are distinct. In what follows, the phrase "acting with free
will" means engaging in an action as the result of the utilization of
free will. Use of the phrase does not deny the distinction between
free will and free action.
The second reason to care about free will is that it seems to be
required for moral responsibility. While there are various accounts of
what exactly moral responsibility is, it is widely agreed that moral
responsibility is distinct from causal responsibility. Consider a
falling branch that lands on a car, breaking its window. While the
branch is causally responsible for the broken window, it is not
morally responsible for it because branches are not moral agents.
Depending on one's account of causation, it also might be possible to
be morally responsible for an event or state of affairs even if one is
not causally responsible for that same event or state of affairs. For
present purposes, let us simply say that an agent is morally
responsible for an event or state of affairs only if she is the
appropriate recipient of moral praise or moral blame for that event or
state of affairs (an agent can thus be morally responsible even if no
one, including herself, actually does blame or praise her for her
actions). According to the dominant view of the relationship between
free will and moral responsibility, if an agent does not have free
will, then that agent is not morally responsible for her actions. For
example, if Allison is coerced into doing a morally bad act, such as
stealing a car, we shouldn't hold her morally responsible for this
action since it is not an action that she did of her own free will.
Some philosophers do not believe that free will is required for moral
responsibility. According to John Martin Fischer, human agents do not
have free will, but they are still morally responsible for their
choices and actions. In a nutshell, Fischer thinks that the kind of
control needed for moral responsibility is weaker than the kind of
control needed for free will. Furthermore, he thinks that the truth of
causal determinism would preclude the kind of control needed for free
will, but that it wouldn't preclude the kind of control needed for
moral responsibility. See Fischer (1994). As this example shows,
virtually every issue pertaining to free will is contested by various
philosophers.
However, many think that the significance of free will is not limited
to its necessity for free action and moral responsibility. Various
philosophers suggest that free will is also a requirement for agency,
rationality, the autonomy and dignity of persons, creativity,
cooperation, and the value of friendship and love [see Anglin (1990),
Kane (1998) and Ekstrom (1999)]. We thus see that free will is central
to many philosophical issues.
2. Accounts of the Will
Nearly every major figure in the history of philosophy has had
something or other to say about free will. The present section
considers three of the most prominent theories of what the will is.
a. Faculties Model of the Will
The faculties model of the will has its origin in the writings of
ancient philosophers such as Plato and Aristotle, and it was the
dominant view of the will for much of medieval and modern philosophy
[see Descartes (1998) and the discussion of Aquinas in Stump (2003)].
It still has numerous proponents in the contemporary literature. What
is distinct about free agents, according to this model, is their
possession of certain powers or capacities. All living things possess
some capacities, such as the capacities for growth and reproduction.
What is unique about free agents, however, is that they also possess
the capacities for intellection and volition. Another way of saying
this is that free agents alone have the faculties of intellect and
will. It is in virtue of having these additional faculties, and the
interaction between them, that agents have free will.
The intellect, or the rational faculty, is the power of cognition. As
a result of its cognitions, the intellect presents various things to
the will as good under some description. To return to the case of
Allison contemplating walking her dog, Allison's intellect might
evaluate walking the dog as good for the health of the dog.
Furthermore, all agents that have an intellect also have a will. The
will, or the volitional faculty, is an appetite for the good; that is,
it is naturally drawn to goodness. The will, therefore, cannot pursue
an option that the intellect presents as good in no way. The will is
also able to command the other faculties; the will can command the
body to move or the intellect to consider something. In the case of
Allison, the will could command the body to pick up the leash, attach
it to the dog, and go outside for a walk. As Aquinas, a proponent of
the this view of the will, puts it: "Only an agent endowed with an
intellect can act with a judgment which is free, in so far as it
apprehends the common note of goodness; from which it can judge this
or the other thing to be good. Consequently, wherever there is
intellect, there is free will" (Summa Theologiae, q. 59 a. 3). Thus,
through the interaction between the intellect and will, an agent has
free will to pursue something that it perceives as good.
b. Hierarchical Model of the Will
A widely influential contemporary account of the will is Harry
Frankfurt's hierarchical view of the will [see Frankfurt (1971)]. This
account is also sometimes called a "structuralist" or "mesh" account
of the will, since a will is free if it has a certain internal
structure or "mesh" among the various levels of desires and volitions.
According to the hierarchical model, agents can have different kinds
of desires. Some desires are desires to do a particular action; for
example, Allison may desire to go jogging. Call these desires "1st
order desires." But even if Allison doesn't desire to go jogging, she
may nevertheless desire to be the kind of person who desires to go
jogging. In other words, she may desire to have a certain 1st order
desire. Call desires of this sort "2nd order desires." If agents also
have further desires to have particular 2nd order desires, one could
construct a seemingly infinite hierarchy of desires.
Not all of an agent's desires result in action. In fact, if one has
conflicting desires, then it is impossible for an agent to satisfy all
her desires. Suppose that Allison not only desires to run, but that
she also desires to stay curled up in bed, where it is nice and warm.
In such a case, Allison cannot fulfill both of her 1st order desires.
If Allison decides to act on her desire to run, we say that her desire
to run has moved her to action. An effective desire of this sort is
called a volition; a volition is a desire that moves the agent all the
way to action. Similarly, one can differentiate between a mere 2nd
order desire (simply a desire to have a certain desire) and a 2nd
order volition (a desire for a desire to become one's will, or a
desire for a desire to become a volition). According to the
hierarchical view of the will, free will consists in having 2nd order
volitions. In other words, an agent has a free will if she is able to
have the sort of will that she wants to have. An agent acts on her own
free will if her action is the result of a 1st order desire that she
wants to become a 1st order volition.
Hierarchical views of the will are problematic, however, because it
looks as if certain sorts of questionable manipulation can be
compatible with this view's account of free will. According to the
view under consideration, Allison has free will with regard to going
jogging if she has a 2nd order desire that her 1st order desire to go
jogging will move her to go jogging. Nothing in this account, however,
depends on how she got these desires. Even if she were manipulated,
via brainwashing, for example, into having her 2nd order desire for
her 1st order desire to go running become her will, Allison has the
right "mesh" between her various orders of desires to qualify as
having free will. This is an untoward consequence. While more robust
hierarchical accounts of the will have the resources for explaining
why Allison might not be free in this case, it is widely agreed that
cases of manipulation and coercion are problematic for solely
structural accounts of the will [see Ekstrom (1999), Fischer (1994),
Kane, (2005), Pereboom (2001) and van Inwagen (1983)].
c. Reasons-Responsive View of the Will
A third treatment of free will takes as its starting point the claim
that agency involves a sensitivity to certain reasons. An agent acts
with free will if she is responsive to the appropriate rational
considerations, and she does not act with a free will if she lacks
such responsiveness. To see what such a view amounts to, consider
again the case of Allison and her decision to walk her dog. A
reasons-responsive view of the will says that Allison's volition to
walk her dog is free if, had she had certain reasons for not walking
her dog, she would not have decided to walk her dog. Imagine what
would have happened had Allison turned on the television after waking
from her nap and learned of the blizzard before deciding to walk her
dog. Had she known of the blizzard, she would have had a good reason
for deciding not to walk her dog. Even if such reasons never occur to
her (that is, if she doesn't learn of the blizzard before her
decision), her disposition to have such reasons influence her
volitions shows that she is responsive to reasons. Thus,
reasons-responsive views of the will are essentially dispositional in
nature.
Coercion and manipulation undermine free will, on this view, in virtue
of making agents not reasons-responsive. If Allison has been
brainwashed to walk the dog at a certain time, then even if she were
to turn on the news and sees that it is snowing, she would attempt to
walk the dog despite having good reasons not to. Thus, manipulated
agents are not reasons-responsive, and in virtue of this lack free
will. [See Fischer and Ravizza (1998) for one of the primary
reasons-responsive views of free will.]
3. Free Will and Determinism
a. The Thesis of Causal Determinism
Most contemporary scholarship on free will focuses on whether or not
it is compatible with causal determinism. Causal determinism is
sometimes also called "nomological determinism." It is important to
keep causal determinism distinct from other sorts of determinism, such
as logical determinism or theological determinism (to be discussed
below). Causal determinism (hereafter, simply "determinism") is the
thesis that the course of the future is entirely determined by the
conjunction of the past and the laws of nature. Imagine a proposition
that completely describes the way that the entire universe was at some
point in the past, say 100 million years ago. Let us call this
proposition "P." Also imagine a proposition that expresses the
conjunction of all the laws of nature; call this proposition "L."
Determinism then is the thesis that the conjunction of P and L entails
a unique future. Given P and L, there is only one possible future, one
possible way for things to end up. To make the same point using
possible world semantics, determinism is the thesis that all the
states of affairs that obtain at some time in the past, when conjoined
with the laws of nature, entail which possible world is the actual
world. Since a possible world includes those states of affairs that
will obtain, the truth of determinism amounts to the thesis that the
past and the laws of nature entail what states of affairs will obtain
in the future, and that only those states of affairs entailed by the
past and the laws will in fact obtain.
A system's being determined is different from its being predictable.
It is possible for determinism to be true and for no one to be able to
predict the future. The fact that no human agent knows or is able to
know future truths has no bearing on whether there are future truths
entailed by the conjunction of the past and the laws. However, there
is a weaker connection between the thesis of determinism and the
predictability of the future. If determinism were true, then a being
with a complete knowledge of P and L and with sufficient intellective
capacities should be able to infallibly predict the way that the
future will turn out. However, given that we humans lack both the
relevant knowledge and the intellective capacities required, the fact
that we are not able to predict the future is not evidence for the
falsity of determinism.
b. Determinism, Science and "Near Determinism"
Most philosophers agree that whether or not determinism is true is a
contingent matter; that is, determinism is neither necessarily true
nor necessarily false. If this is so, then whether or not determinism
is true becomes an empirical matter, to be discovered by investigating
the way the world is, not through philosophical argumentation. This is
not to deny that the truth of determinism would have metaphysical
implications. For one, the truth of determinism would entail that the
laws of nature are not merely probabilistic—for if they were, then the
conjunction of the past and the laws would not entail a unique future.
Furthermore, as we shall see shortly, philosophers care very much
about what implications the truth of determinism would have for free
will. But the point to note is that if the truth of determinism is a
contingent truth about the way the world actually is, then scientific
investigation should give us insight into this matter. Let us say that
a possible world is deterministic if causal determinism is true in
that world. There are two ways that worlds could fail to be
deterministic. As already noted, if the laws of nature in a given
world were probabilistic, then such a world would not be
deterministic. Secondly, if there are entities within a world that are
not fully governed by the laws of nature, then even if those laws are
themselves deterministic, that world would not be deterministic.
Some scientists suggest that certain parts of physics give us reason
to doubt the truth of determinism. For example, the standard
interpretation of Quantum Theory, the Copenhagen Interpretation, holds
that the laws governing nature are indeterministic and probabilistic.
According to this interpretation, whether or not a small particle such
as a quark swerves in a particular direction at a particular time is
described properly only by probabilistic equations. Although the
equations may predict the likelihood that a quark swerves to the left
at a certain time, whether or not it actually swerves is
indeterministic or random.
There are also deterministic interpretations of Quantum Theory, such
as the Many-Worlds Interpretation. Fortunately, the outcome of the
debate regarding whether Quantum Theory is most properly interpreted
deterministically or indeterminstically, can be largely avoided for
our current purposes. Even if (systems of) micro-particles such as
quarks are indeterministic, it might be that (systems involving)
larger physical objects such as cars, dogs, and people are
deterministic. It is possible that the only indeterminism is on the
scale of micro-particles and that macro-objects themselves obey
deterministic laws. If this is the case, then causal determinism as
defined above is, strictly speaking, false, but it is "nearly" true.
That is, we could replace determinism with "near determinism," the
thesis that despite quantum indeterminacy, the behaviors of all large
physical objects—including all our actions—obey deterministic laws
[see Honderich (2002), particularly chapter 6].
What would be the implications of the truth of either determinism or
near determinism? More specifically, what would be the implications
for questions of free will? One way to think about the implications
would be by asking the following the question: could we still be free
even if scientists were to discover that causal determinism (or near
determinism) is true?
c. Compatibilism, Incompatibilism, and Pessimism
The question at the end of the preceding section (Could we have free
will even if determinism is true?) is a helpful way to differentiate
the main positions regarding free will. Compatibilists answer this
question in the affirmative. They believe that agents could have free
will even if causal determinism is true (or even if near determinism
is true. In what follows, I will omit this qualification). In other
words, the existence of free will in a possible world is compatible
with that world being deterministic. For this reason, this position is
known as "compatibilism," and its proponents are called
"compatibilists." According to the compatibilist, it is possible for
an agent to be determined in all her choices and actions and still
make some of her choices freely.
According to "incompatibilists," the existence of free will is
incompatible with the truth of determinism. If a given possible world
is deterministic, then no agent in that world has free will for that
very reason. Furthermore, if one assumes that having free will is a
necessary condition for being morally responsible for one's actions,
then the incompatibility of free will and determinism would entail the
incompatibility of moral responsibility and causal determinism.
There are at least two kinds of incompatibilists. Some
incompatibilists think that determinism is true of the actual world,
and thus no agent in the actual world possesses free will. Such
incompatibilists are often called "hard determinists" [see Pereboom
(2001) for a defense of hard determinism]. Other incompatibilists
think that the actual world is not deterministic and that at least
some of the agents in the actual world have free will. These
incompatibilists are referred to as "libertarians" [see Kane (2005),
particularly chapters 3 and 4]. However, these two positions are not
exhaustive. It is possible that one is an incompatibilist, thinks that
the actual world is not deterministic, and yet still thinks that
agents in the actual world do not have free will. While it is less
clear what to call such a position (perhaps "free will deniers"), it
illustrates that hard determinism and libertarianism do not exhaust
the ways to be an incompatibilist. Since all incompatibilists,
whatever their stripe, agree that the falsity of determinism is a
necessary condition for free will, and since compatibilists deny this
assertion, the following sections speak simply of incompatibilists and
compatibilists.
It is also important to keep in mind that both compatibilism and
incompatibilism are claims about possibility. According to the
compatibilist, it is possible that an agent is both fully determined
and yet free. The incompatibilist, on the other hand, maintains that
such a state of affairs is impossible. But neither position by itself
is making a claim about whether or not agents actually do possess free
will. Assume for the moment that incompatibilism is true. If the truth
of determinism is a contingent matter, then whether or not agents are
morally responsible will depend on whether or not the actual world is
deterministic. Furthermore, even if the actual world is
indeterministic, it doesn't immediately follow that the indeterminism
present is of the sort required for free will (we will return to a
similar point below when considering an objection to incompatibilism).
Likewise, assume both that compatibilism is true and that causal
determinism is true in the actual world. It does not follow from this
that agents in the actual world actually possess free will.
Finally, there are free will pessimists [see Broad (1952) and G.
Strawson (1994)]. Pessimists agree with the incompatibilists that free
will is not possible if determinism is true. However, unlike the
incompatibilists, pessimists do not think that indeterminism helps. In
fact, they claim, rather than helping support free will, indeterminism
undermines it. Consider Allison contemplating taking her dog for a
walk. According to the pessimist, if Allison is determined, she cannot
be free. But if determinism is false, then there will be indeterminacy
at some point prior to her action. Exactly where one locates this
indeterminacy will depend on one's particular view of the nature of
free will. Let us assume that that indeterminacy is located in which
reasons occur to Allison. It is hard to see, the pessimist argues, how
this indeterminacy could enhance Allison's free will, for it the
occurrence of her reasons is indeterministic, then having those
reasons is not within Allison's control. But if Allison decides on the
basis of whatever reasons she does have, then her volition is based
upon something outside of her control. It is based instead on chance.
Thus, pessimists think that the addition of indeterminism actually
makes agents lack the kind of control needed for free will. While
pessimism might seem to be the same position as that advocated by free
will deniers, pessimism is a stronger claim. Free will deniers thinks
that while free will is possible, it just isn't actual: agents in fact
don't have free will. Pessimists, however, have a stronger position,
thinking that free will is impossible. Not only do agents lack free
will, there is no way that they could have it [see G. Strawson
(1994)]. The only way to preserve moral responsibility, for the
pessimist, is thus to deny that free will is a necessary condition for
moral responsibility.
As pessimism shows us, even a resolution to the debate between
compatibilists and incompatibilists will not by itself solve the
debate about whether or not we actually have free will. Nevertheless,
it is to this debate that we now turn.
4. Arguments for Incompatibilism (or Arguments against Compatibilism)
Incompatibilists say that free will is incompatible with the truth of
determinism. Not all arguments for incompatibilism can be considered
here; let us focus on two major varieties. The first variety is built
around the idea that having free will is a matter of having a choice
about certain of our actions, and that having a choice is a matter of
having genuine options or alternatives about what one does. The second
variety of arguments is built around the idea that the truth of
determinism would mean that we don't cause our actions in the right
kind of way. The truth of determinism would mean that we don't
originate our actions in a significant way and our actions are not
ultimately controlled by us. In other words, we lack the ability for
self-determination. Let us consider a representative argument from
each set.
a. The Consequence Argument
The most well-known and influential argument for incompatibilism from
the first set of arguments is called the "Consequence Argument," and
it has been championed by Carl Ginet and Peter van Inwagen [see Ginet
(1966) and van Inwagen (1983)]. The Consequence Argument is based on a
fundamental distinction between the past and the future. First,
consider an informal presentation of this argument. There seems to be
a profound asymmetry between the past and the future based on the
direction of the flow of time and the normal direction of causation.
The future is open in a way that the past is not. It looks as though
there is nothing that Allison can now do about the fact that Booth
killed Lincoln, given that Lincoln was assassinated by Booth in 1865.
This point stands even if we admit the possibility of time travel. For
if time travel is possible, Allison can influence what the past
became, but she cannot literally change the past. Consider the
following argument:
1. The proposition "Lincoln was assassinated in 1865″ is true.
2. If Allison travels to the past, she could prevent Lincoln from
being assassinated in 1865 (temporarily assumed for reductio
purposes).
3. If Allison were to travel to the past and prevent Lincoln from
being assassinated in 1865, the proposition "Lincoln was assassinated
in 1865″ would be false.
4. A proposition cannot both be true and false.
5. Therefore, 2 is false.
So, at most the possibility of time travel allows for agents to have
causal impact on the past, not for agents to change what has already
become the past. The past thus appears to be fixed and unalterable.
However, it seems that the same is not true of the future, for Allison
can have an influence on the future through her volitions and
subsequent actions. For example, if she were to invent a time machine,
then she could, at some point in the future, get in her time machine
and travel to the past and try to prevent Lincoln from being
assassinated. However, given that he was assassinated, we can infer
that her attempts would all fail. On the other hand, she could refrain
from using her time machine in this way.
The asymmetry between past and future is illustrated by the fact that
we don't deliberate about the past in the same way that we deliberate
about the future. While Allison might deliberate about whether a past
action was really the best action that she could have done, she
deliberates about the future in a different way. Allison can question
whether her past actions were in fact the best, but she can both
question what future acts would be best as well as which future acts
she should perform. Thus, it looks like the future is open to Allison,
or up to her, in a way that the past is not. In other words, when an
agent like Allison is using her free will, what she is doing is
selecting from a range of different options for the future, each of
which is possible given the past and the laws of nature. For this
reason, this view of free will is often called the "Garden of Forking
Paths Model."
The Consequence Argument builds upon this view of the fixed nature of
the past to argue that if determinism is true, the future is not open
in the way that the above reflections suggest. For if determinism is
true, the future is as fixed as is the past. Remember from the above
definition that determinism is the thesis the past (P) and the laws of
nature (L) entail a unique future. Let "F" refer to any true
proposition about the future. The Consequence argument depends on two
modal operators, and two inference rules. Let the modal operator "L"
abbreviate "It is logically necessary that..," so that, when it
operates on some proposition p, "Lp" abbreviates "It is logically
necessary that p." Let the modal operator "N" be such that "Np" stands
for "p is true and no one has, or ever had, any choice about whether p
was true." Call the following two inference rules "Alpha" and "Beta:"
Alpha: Lp implies Np Beta: {Np and N(p → q)} implies Nq
According to Alpha, if p is a necessary truth, then no one has, or
ever had, any choice about whether pwas true. Similarly, according to
Beta, if no one has, or ever had, any choice about p being true, and
no one has, or ever had, any choice that p entails q, then no one has,
or ever had, any choice about whetherq is true. To see the
plausibility of Beta, consider the following application. Let p be the
proposition "The earth was struck by a meteor weighing 100 metric tons
one billion years ago," and let q be the proposition "If the earth was
struck by a meteor weighing 100 metric tons one billion years ago,
then thousands of species went extinct." Since I have no choice about
such a meteor hitting in the past, and have no choice that if such
meteor hits, it will cause thousands of species to go extinct, I have
no choice that thousands of species went extinct. Beta thus looks
extremely plausible. But if Beta is true, then we can construct an
argument to show that if determinism is true, then I have no choice
about anything, including my supposed free actions in the future. The
argument begins with the definition of determinism given above:
(1) L{(P and L) → F}
Using a valid logical rule of inference (exportation), we can
transform 1 into 2:
(2) L{P → (L → F)}
Applying Alpha, we can derive 3:
(3) N{P → (L → F)}
The second premise in the Consequence Argument is called the "fixity
of the past." No one has, or ever had, a choice about the true
description P of the universe at some point in the distant past:
(4) NP
From 3, 4 and Beta, we can deduce 5:
(5) N(L → F)
The final premise in the argument is the fixity of the laws of nature.
No one has, or ever had, a choice about what the laws of nature are
(try as I might, I cannot make the law of universal gravitation not be
a law of nature):
(6) NL
And from 5 and 6, again using Beta, we can infer that no one has, or
ever had, a choice about F:
(7) NF
Given that F was any true proposition about the future, the
Consequence Argument concludes that if determinism is true, then no
one has or ever had a choice about any aspect of the future, including
what we normally take to be our free actions. Thus, if determinism is
true, we do not have free will.
b. The Origination Argument
The second general set of arguments for the incompatibility of free
will and determinism builds on the importance of the source of a
volition for free will. Again, it will be helpful to begin with an
informal presentation of the argument before considering a formal
presentation of it. According to this line of thought, an agent has
free will when her volitions issue from the agent herself in a
particular sort of way (say, her beliefs and desires). What is
important for free will, proponents of this argument claim, is not
simply that the causal chain for an agent's volition goes through the
agent, but that it originates with the agent. In other words, an agent
acts with free will only if she originates her action, or if she is
the ultimate source or first cause of her action [see Kane (1998)].
Consider again the claim that free will is a necessary condition for
moral responsibility. What reflection on cases of coercion and
manipulation suggests to us is that even if a coerced or manipulated
agent is acting on her beliefs and desires, this isn't enough for
moral responsibility. We normally assume that coercion and certain
forms of manipulation undercut an agent's moral responsibility
precisely because a coerced or manipulated agent isn't the originator
of her coerced action. If Allison is coerced into walking her dog via
brainwashing, then her walking of the dog originates in the
brainwashing, and not in Allison herself. Consider, then, the
similarities between cases of coercion and manipulation, on the one
hand, and the implications of the truth of determinism on the other.
If determinism were true, it might be true that Allison chooses to
walk her dog because of her beliefs and desires, but those beliefs and
desires would themselves be the inevitable products of causal chains
that began millions of years ago. Thus, a determined agent is at most
a source, but not the ultimate source, of her volitions. According to
proponents of this sort of argument for incompatibilism, the truth of
determinism would mean that agents don't cause their actions in the
kind of way needed for free will and, ultimately, moral
responsibility.
We can represent a formal version of the argument, called the
"Origination Argument," as follows:
1. An agent acts with free will only if she is the originator (or
ultimate source) of her actions.
2. If determinism is true, then everything any agent does is
ultimately caused by events and circumstances outside her control.
3. If everything an agent does is ultimately caused by events and
circumstances beyond her control, then the agent is not the originator
(or ultimate source) of her actions.
4. Therefore, if determinism is true, then no agent is the
originator (or ultimate source) of her actions.
5. Therefore, if determinism is true, no agent has free will.
The Origination Argument is valid. So, in evaluating its soundness, we
must evaluate the truth of its three premises. Premise 3 is clearly
true, since for an agent to be an originator just is for that agent
not to be ultimately determined by anything outside of herself.
Premise 2 of this argument is true by the definition of determinism.
To reject the conclusion of the argument, one must therefore reject
premise 1.
Earlier we briefly noted one account of free will which implicitly
denies premise 1, namely the hierarchical model of free will.
According to this model, an agent acts with free will so long as the
causal chain for that action goes through the agent's 1st- and
2nd-order desires. One way of emphasizing the need for origination
over-against such a hierarchical model is to embrace agent-causation.
If premise 1 is true, then the agent's volition cannot be the product
of a deterministic causal chain extended beyond the agent. What other
options are there? Two options are that volitions are uncaused, or
only caused indeterministically. It is difficult to see how an agent
could be the originator or ultimate source of volitions if volitions
are uncaused. Similarly, for reasons we saw above when discussing the
free will pessimist, it looks as if indeterministic causation would
undermine, rather than enhance, an agent's control over her volitions.
For these reasons, some incompatibilists favor looking at the
causation involved in volitions in a new light. Instead of holding
that a volition is caused by a previous event (either
deterministically or indeterministically), these incompatibilists
favor saying that volitions are caused directly by agents. [For an
extended defense of this view, see O'Connor, (2000).] They hold that
there are two irreducibly different kinds of causation,
event-causation and agent-causation, and the latter is involved in
free will. Proponents of agent-causation propose that agents are
enduring substances that directly possess the power to cause
volitions. Although many philosophers question whether agent-causation
is coherent, if it were coherent, then it would provide support for
premise 1 of the Origination Argument.
c. The Relation between the Arguments
The above way of delineating the Consequence and Origination Arguments
may unfortunately suggest that the two kinds of arguments are more
independent from each other than they really are. A number of
incompatibilists have argued that agents originate their actions in
the way required by premise 1 of the Origination Argument if and only
if they have a choice about their actions in the way suggested by the
Consequence Argument. In other words, if my future volitions are not
the sort of thing that I have a choice about, then I do not originate
those volitions. And as the above arguments contend, the truth of
causal determinism threatens both our control over our actions and
volitions, and our ability to originate those same actions and
volitions. For if causal determinism is true, then the distant past,
when joined with the laws of nature, is sufficient for every volition
that an agent makes, and the causal chains that lead to those
volitions would not begin within the agent. Thus, most
incompatibilists think that having a choice and being a
self-determiner go hand-in-hand. Robert Kane, for instance, argues
that if agents have "ultimate responsibility" (his term for what is
here called "origination" or "self-determination"), then they will
also have alternative possibilities open to them. According to this
line of argumentation, the power to cause one's own actions is not a
distinct power from the power to choose and do otherwise. Thus, the
two different kinds of arguments for incompatibilism may simply be two
sides of the same coin [see Kane (1996) and (2005)].
5. Arguments for Compatibilism (or Arguments against Incompatibilism)
Having laid out representatives of the two most prominent arguments
for incompatibilism, let's consider arguments in favor of
compatibilism. In considering these kinds of arguments, it is
pedagogically useful to approach them by using the arguments for
incompatibilism. So, this section begins by considering ways that
compatibilists have responded to the arguments given in the preceding
section.
a. Rejecting the Incompatibilist Arguments
As noted above, the Origination Argument for incompatibilism is valid,
and two of its premises are above dispute. Thus, the only way for the
compatibilist to reject the conclusion of the Origination Argument is
to reject its first premise. In other words, given the definition of
determinism, compatibilists must reject that free will requires an
agent being the originator or ultimate source of her actions. But how
might this be done? Most frequently, compatibilists motivate a
rejection of the "ultimacy condition" of free will by appealing to
either a hierarchical or reasons-responsive view of what the will is
[see Frankfurt, (1971) and Fischer and Ravizza, (1998)]. If all that
is required for free will, for example, is that a certain mesh between
an agent's 1st-order volitions and 2nd-order desires, then such an
account does not require that an agent be the originator of those
desires. Furthermore, since the truth of determinism would not entail
that agents don't have 1st and 2nd-order desires and volitions, a
hierarchical account of the will is compatible with the truth of
determinism. Similarly, if an agent has free will if she has the
requisite level of reasons-responsiveness such that she would have
willed differently had she had different reasons, ultimacy is again
not required. Thus, if one adopts certain accounts of the will, one
has reason for rejecting the central premise of the Origination
Argument.
Compatibilists have a greater number of responses available to them
with regard to the Consequence Argument. One way of understanding the
N operator that figures in the Consequence Argument is in terms of
having the ability to do otherwise. That is, to say that Allison has
no choice about a particular action of hers is to say that she could
not have performed a different action (or even no action at all).
Incompatibilists can easily account for this ability to do otherwise.
According to incompatibilists, an agent can be free only if
determinism is false. Consider again the case of Allison. If
determinism is false, even though Allison did choose to walk her dog,
she could have done otherwise than walk her dog since the conjunction
of P and L is not sufficient for her taking her dog for a walk.
Compatibilists, however, can give their own account of the ability to
do otherwise. For them, to say that Allison could have done otherwise
is simply to say that Allison would have done otherwise had she willed
or chosen to do so [see, for example, Chisholm (1967)]. Of course, if
determinism is true, then the only way that Allison could have willed
or chosen to do otherwise would be if either the past or the laws were
different than they actually are. In other words, saying that an agent
could have done otherwise is to say that the agent would have done
otherwise in a different counterfactual condition. But saying this is
entirely consistent with one way of understanding the ability to do
otherwise. Thus, these compatibilists are saying that Allison has the
ability to do something such that, had she done it, either the past or
the laws of nature would have been different than they actually are.
If P and L entail that the agent does some action A, then the agent's
doing otherwise than A entails that either P or L would have been
different than they actually are. Some compatibilists favor saying
that agent's have this counterfactual power over the past, while
others favor counterfactual power over the laws of nature [Compare
Lewis (1981) and Fischer (1984)]. Regardless, adopting either strategy
provides the compatibilist with a way of avoiding the conclusion of
the Consequence Argument by denying either premise 4 or premise 6 of
that argument. Furthermore, having such a power is not a hollow
victory, for it demarcates a plausible difference between those
actions an agent would have done even if she didn't want to (as in the
case of coercion or manipulation) from those actions that an agent
only would have done had she had certain beliefs and desires about
that action. This view thus differentiates between those actions that
were within the agent's power to bring about from those that were not.
A second compatibilist response to the Consequence Argument is to deny
the validity of the inference rule Beta the argument uses. While there
are several approaches to this, perhaps the most decisive is the
following, called the principle of Agglomeration [see McKay and
Johnson (1996)]. Using only the inference rules Alpha, Beta and basic
rule of logical replacement, one can show that
(1) Np
and
(2) Nq
would entail
(3) N(p and q)
if Beta were valid. 1 and 2 do not entail 3, so Beta must be invalid.
To see why 3 does not follow from 1 and 2, consider the case of a
coin-toss. If the coin-toss is truly random, then Allison has no
choice regarding whether the coin (if flipped) lands heads. Similarly,
she has no choice regarding whether the coin (again, if flipped) lands
tails. For purposes of simplicity, let us stipulate that the coin
cannot land on its side and, if flipped, must land either heads or
tails. Let p above represent 'the coin doesn't land heads' and q
represent 'the coin doesn't land tails'. If Beta were valid, then 1
and 2 would entail 3, and Allison would not have a choice about the
conjunction of p and q; that is, she wouldn't have a choice about the
coin not landing heads and the coin not landing tails. If Allison
didn't have a choice about the coin not landing heads and didn't have
a choice about the coin not landing heads, then she wouldn't have a
choice about the coin landing either heads or tails. But Allison does
have a choice about this—after all, she can ensure that the coin lands
either heads or tails by simply flipping the coin. So Allison does
have a choice about the conjunction of p and q. Since Alpha and the
relevant rules of logical replacement in the transformation from Np
and Np to N(p and q) are beyond dispute, Beta must be invalid. Thus,
the Consequent Argument for incompatibilism is invalid. [For an
incompatibilist reply to the argument from Agglomeration, see Finch
and Warfield (1998).]
b. Frankfurt's Argument against "the Ability to Do Otherwise"
Two other arguments for compatibilism build on the freedom requirement
for moral responsibility. If one can show that moral responsibility is
compatible with the truth of determinism, and if free will is required
for moral responsibility, one will have implicitly shown that free
will is itself compatible with the truth of determinism. The first of
these arguments for compatibilism rejects the understanding of having
a choice as involving the ability to do otherwise mentioned above.
While most philosophers have tended to accept that an agent can be
morally responsible for doing an action only if she could have done
otherwise, Harry Frankfurt has attempted to show that this requirement
is in fact false. Frankfurt gives an example in which an agent does an
action in circumstances that lead us to believe that the agent acted
freely [Frankfurt (1969); for recent discussion, see Widerker and
McKenna (2003)]. Yet, unbeknown to the agent, the circumstances
include some mechanism that would bring about the action if the agent
did not perform it on her own. As it happens, though, the agent does
perform the action freely and the mechanism is not involved in
bringing about the action. It thus looks like the agent is morally
responsible despite not being able to do otherwise. Here is one such
scenario:
Allison is contemplating whether to walk her dog or not. Unbeknown
to Allison, her father, Lloyd, wants to insure that that she does
decide to walk the dog. He has therefore implanted a computer chip in
her head such that if she is about to decide not to walk the dog, the
chip will activate and coerce her into deciding to take the dog for a
walk. Given the presence of the chip, Allison is unable not to decide
to walk her dog, and she lacks the ability to do otherwise. However,
Allison does decide to walk the dog on her own.
In such a case, Frankfurt thinks that Allison is morally responsible
for her decision since the presence of Lloyd and his computer chip
play no causal role in her decision. Since she would have been morally
responsible had Lloyd not been prepared to ensure that she decide to
take her dog for a walk, why think that his mere presence renders her
not morally responsible? Frankfurt concludes that Allison is morally
responsible despite lacking the ability to do otherwise. If Frankfurt
is right that such cases are possible, then even if the truth of
determinism is incompatible with a kind of freedom that requires the
ability to do otherwise, it is compatible with the kind of freedom
required for moral responsibility.
c. Strawson's Reactive Attitudes
In an influential article, Peter Strawson argues that the many of the
traditional debates between compatibilists and incompatibilists (such
as how to understand the ability to do otherwise) are misguided [P.
Strawson (1963)]. Strawson thinks that we should instead focus on what
he calls the reactive attitudes—those attitudes we have toward other
people based on their attitudes toward and treatment of us. Strawson
says that the hallmark of reactive attitudes is that they are
"essentially natural human reactions to the good or ill will or
indifference of others toward us, as displayed in their attitudes and
actions." Examples of reactive attitudes include gratitude,
resentment, forgiveness and love. Strawson thinks that these attitudes
are crucial to the interpersonal interactions and that they provide
the basis for holding individuals morally responsible. Strawson then
argues for two claims. The first of these is that an agent's reactive
attitudes would not be affected by a belief that determinism was true:
The human commitment to participation in ordinary interpersonal
relationships is, I think, too thoroughgoing and deeply rooted for us
to take seriously the thought that a general theoretical conviction
might so change our world that, in it, there were no longer such
things as inter-personal relationships as we normally understand
them.… A sustained objectivity of inter-personal attitude, and the
human isolation which that would entail, does not seem to be something
of which human beings would be capable, even if some general truth
were a theoretical ground for it.
Furthermore, Strawson also argues for a normative claim: the truth of
determinism should not undermine our reactive attitudes. He thinks
that there are two kinds of cases where it is appropriate to suspend
our reactive attitudes. One involves agents, such as young children or
the mentally disabled, who are notmoral agents. Strawson thinks that
we should not have reactive attitudes toward non-moral agents. The
second kind of case where it is appropriate to suspend our reactive
attitudes are those in which while the agent is a moral agent, her
action toward us is not connected to her agency in the correct way.
For instance, while I might have the reactive attitude of resentment
towards someone who bumps into me and makes me spill my drink, if I
were to find out that the person was pushed into me, I would not be
justified in resenting that individual. The truth of determinism,
however, would neither entail that no agents are moral agents nor that
none of an agent's actions are connected to her moral agency. Thus,
Strawson thinks, the truth of determinism should not undermine our
reactive attitudes. Since moral responsibility is based on the
reactive attitudes, Strawson thinks that moral responsibility is
compatible with the truth of determinism. And if free will is a
requirement for moral responsibility, Strawson's argument gives
support to compatibilism.
6. Related Issues
The above discussion should help explain the perennial attraction
philosophers have to the issues surrounding free will, particularly as
it relates to causal determinism. However, free will is also
intimately related to a number of other recurrent issues in the
history of philosophy. In this final section, I will briefly
articulate two other kinds of determinism and show how they are
connected to free will.
a. Theological Determinism
The debate about free will and causal determinism parallels, in many
ways, another debate about free will, this one stemming from what is
often called 'theological determinism'. Some religious traditions hold
that God is ultimately responsible for everything that happens.
According to these traditions, God's willing x is necessary and
sufficient for x. But if He is ultimately responsible for everything
in virtue of what He wills, then He is ultimately responsible for all
the actions and volitions performed by agents. God's willing that
Allison take the dog for a walk is thus necessary and sufficient for
Allison taking the dog for a walk. But if this is true, it is hard to
see how Allison could have free will. The problem becomes especially
astute when considering tradition doctrines of eternal punishment. The
traditional Christian doctrine of Hell, for example, is that Hell is a
place of eternal punishment for non-repentant sinners. But if
theological determinism is true, then whether or not agents repent is
ultimately up to God, not to the agents themselves. This worry over
free will thus gives rise to a particular version of the problem of
evil: why does God not will that all come to faith, when His having
such a will is sufficient for their salvation? [For a discussion of
these, and related issues, see Helm, (1994).]
b. Logical Determinism
In addition to the causal and theological forms of determinism, there
is also logical determinism. Logical determinism builds off the law of
excluded middle and holds that propositions about what agents will do
in the future already have a truth value. For instance, the
proposition "Allison will take the dog for a walk next Thursday" is
already true or false. Assume that it is true. Since token
propositions cannot change in truth value over time, it was true a
million years ago that Allison would walk her dog next Thursday. But
the truth of the relevant proposition is sufficient for her actually
taking the dog for a walk (after all, if it is true that she will walk
the dog, then she will walk the dog). But then it looks like no matter
what happens, Allison will in fact take her dog for a walk next
Thursday and that this has always been the case. However, it is hard
to see how Allison's deciding to walk the dog can be a free decision
since she must (given that the relevant token proposition is true and
was true a million years ago) decide to walk him. In response to this
problem, some philosophers have attempted to show that free will is
compatible with the existence of true propositions about what we will
do in the future, and others have denied that propositions about
future free actions have a truth value, that is, that the law of
excluded middle fails for some propositions. [For an introduction to
these issues, see Finch and Warfield, (1999) and Kane, (2002).] If God
is a being who knows the truth value of every proposition, this debate
also connects with the debate over the relationship between divine
foreknowledge and free will.
From this brief survey, we see that free will touches on central
issues in metaphysics, philosophy of human nature, action theory,
ethics and the philosophy of religion. Furthermore, we've seen that
there are competing views regarding virtually every aspect of free
will (including whether there is, or even could be, such a thing).
Perhaps this partially explains the perennial philosophical interest
in the topic.
7. References and Further Reading
* Anglin, W. S. (1990). Free Will and the Christian Faith (Clarendon Press).
* Broad, C. D. (1952). "Determinism, Indeterminism, and
Libertarianism," in Ethics and the History of Philosophy (Routledge
and Kegan Paul).
* Chisholm, Roderick (1967). "He Could Have Done Otherwise,"
Journal of Philosophy 64: 409-417.
* Descartes, René (1998). Discourse on Method and Meditations on
First Philosophy, 4th edition (Hackett Publishing Company).
* Ekstrom, Laura Waddell (1999). Free Will: A Philosophical Study
(HarperCollins Publishers).
* Finch, Alicia and Ted Warfield (1994). "Fatalism: Logical and
Theological," Faith and Philosophy 16.2: 233-238.
* Finch, Alicia and Ted Warfield (1998). "The Mind Argument and
Libertarianism," Mind 107: 515-528.
* Fischer, John Martin (1984). "Power Over the Past," Pacific
Philosophical Quarterly 65: 335-350.
* Fischer, John Martin (1994). The Metaphysics of Free Will (Blackwell).
* Fischer, John Martin and Mark Ravizza (1998). Responsibility and
Control: A Theory of Moral Responsibility (Cambridge University
Press).
* Frankfurt, Harry (1969). "Alternate Possibilities and Moral
Responsibility," reprinted in Pereboom, (1997), pages 156-166.
* Frankfurt, Harry (1971). "Freedom of the Will and the Concept of
a Person," reprinted in Pereboom (1997), pages 167-183.
* Ginet, Carl (1966). "Might We Have No Choice," in Keith Lehrer,
ed., Freedom and Determinism(Random House), pages 205-224.
* Helm, Paul (1994). The Providence of God (InterVarsity Press).
* Honderich, Ted (2002). How Free are You?, 2nd edition (Oxford
University Press).
* Kane, Robert (1998). The Significance of Free Will (Oxford
University Press).
* Kane, Robert, ed. (2001). Free Will (Blackwell).
* Kane, Robert, ed. (2002). The Oxford Handbook of Free Will
(Oxford University Press).
* Kane, Robert (2005). A Contemporary Introduction to Free Will
(Oxford University Press).
* Lewis, David (1981). "Are We Free to Break the Laws?" Theoria
47): 113-121.
* McKay, Thomas and David Johnson (1996). "A Reconsideration of an
Argument against Compatibilism," Philosophical Topics 24: 113-122.
* O'Connor, Timothy (2000). Persons and Causes: The Metaphysics of
Free Will (Oxford University Press).
* Pereboom, Derk, ed. (1997). Free Will (Hackett).
* Pereboom, Derk (2001). Living Without Free Will (Cambridge
University Press).
* Smilansky, Saul (2000). Free Will and Illusion (Clarendon Press).
* Strawson, Galen (1994). "The Impossibility of Moral
Responsibility," Philosophical Studies 75: 5-24.
* Strawson, Peter (1963). "Freedom and Resentment," reprinted in
Pereboom (1997), pages 119-142.
* Stump, Eleonore (2003). Aquinas (Routledge).
* Van Inwagen, Peter (1983). An Essay on Free Will (Clarendon Press).
* Widerker, David and Michael McKenna (2003). Moral Responsibility
and Alternative Possibilities: Essays on the Importance of Alternative
Possibilities (Ashgate).
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