The Consequence Argument: Compatibilism and Incompatibilism
By: Eddie Dodd
Peter Van Inwagen’s book that introduced the term incompatibilism, An Essay on Free
Will, introduces an account against compatibilism and determinism: the consequence argument.
Kadri Vihvelin makes the argument that compatibilism and determinism are true. She even goes
so far as to say that the consequence argument is nothing more than a fatalist fallacy. This paper
will attempt to see who, if either of the two makes the better argument for or against the
consequence argument.
Peter Van Inwagen’s argument defends several arguments for incompatibilism known as
the consequence argument. It follows:
If determinism is true, then our acts are the consequences of the laws of nature and events in the remote
past. But it is not up to us what the laws of nature are. Therefore the consequences of these things
(including our present acts) are not up to us. 1
He follows this argument by laying down rules a B rule a states that no one has or ever had a
choice about whether or not it was true. Rule B If p is the case an on one ever had a choice about
whether or not p is the case. If determinism is true, it is also true that necessarily, if the past was
a certain way before any living things existed, then if the laws of nature are as they are (any
action has occurred). There cannot from this logic be anything said but for example, “I just
raised my arm” and to have this changed would be to also change the laws of nature.
Van Inwagen defends the arguments by saying that a person has had no choice and will
not have a choice about things of the past. He presents the Richard Nixon argument.
(1)Richard Nixon received a pardon for any offences he might have committed while in office
(2)No one had any choice about whether Richard Nixon received a pardon for any offence he
might have committed while in office. 2
1
The Incompatibility of Free Will and Determinism, Peter Van Inwagen; Page 71
Here Van Inwagen rejects determinism.
Kadri Vihvelin’s whole paper surrounds the debate of compatibilism and
incompatibilism. She defends compatibilism, and goes on to define her argument and what she
will be attacking. The incompatibilist believes that determinism is in fact false in the right kind
of way, and that we have free will, or may be a hard determinist who believes determinism is in
fact true and so we don’t have free will. The compatibilist believes that the free will thesis and
determinism can both be true: the set of free will worlds is non-empty and includes deterministic
worlds. The two differ believing that determinism is either compatible or not with determinism.3
Vihvelin’s argument against the consequence argument accepts that the first premise of
the argument is undeniable. The argument that Vihvelin makes that is most compelling is
regarding the defense of the facts of the past. An incompatiblist cannot defend the already
‘fixed’ past. To change that fact, you must be able to do so in a way that does not make it
metaphysically impossible to change a fact. There is no way to change a fact that was up to you
that you have already done. You cannot change the fact that you raised your hand five minutes
ago, yet it was still up to you.
Kadri states that the consequence argument is invalid, we accept the premises yet deny
the conclusion. Her logic is that simply if she would not have raised her hands, according to the
consequence argument, all the laws of the past would be different and the whole past to be
different. However, if one thinks of this to be true, they accept a contradiction. If she would
have raised her hand, the laws of nature would not have been different from what they are.
2
3
The Incompatibility of Free Will and Determinism, Peter Van Inwagen; Page 75
Compatibilism, Incompatbilism, and Impossibilism; Kadri Vihvelin, Page 303
Both arguments are compelling and are strong. Van Inwagen constructs the consequence
argument and makes strong defences. Kadri’s attack on the consequence argument is also
compelling and strong. I agree with Kadri, not for what she did showing the contradiction of the
argument but for showing the circularity of the argument when making a comparison to the
fatalist’s fallacy. The fatalist fallacy is the following:
(1) P
(2) Necessarily, if P then Q
(3) Therefore, it’s necessary that Q. (Q must be the case; q has to be the case; it cannot be otherwise than
Q.)4
So, if someone does something, then they have done that, and there can be no other way than
this. Not only is this argument circular, relying on itself, it fails to recognize the direction of
causation; a direction which always leads from the past to the present. The fatalist argument also
conflates truth and necessity. I mention this argument only because of the fact that the only
difference between the consequence argument and the fatalist fallacy is the fact that the
consequence argument speaks of laws of the past. Since, the laws of the past premise of the
arguments have been proven false. The consequence argument is not sound.
4
Compatibilism, Incompatibilism, Impossibilism; Kadri Vihvelin, Page 308