Kavka's toxin puzzle is a
thought experiment
A thought experiment is a hypothetical situation in which a hypothesis, theory, or principle is laid out for the purpose of thinking through its consequences.
History
The ancient Greek ''deiknymi'' (), or thought experiment, "was the most anc ...
about the possibility of forming an intention to perform an act which, following from reason, is an action one would not actually perform. It was presented by moral and political philosopher Gregory S. Kavka in "The Toxin Puzzle" (1983), and grew out of his work in
deterrence theory
Deterrence theory refers to the scholarship and practice of how threats or limited force by one party can convince another party to refrain from initiating some other course of action. The topic gained increased prominence as a military strategy ...
and
mutual assured destruction
Mutual assured destruction (MAD) is a doctrine of military strategy and national security policy which posits that a full-scale use of nuclear weapons by an attacker on a nuclear-armed defender with second-strike capabilities would cause the ...
.
The puzzle
Kavka's original version of the puzzle is the following:
An eccentric billionaire places before you a vial of toxin that, if you drink it, will make you painfully ill for a day, but will not threaten your life or have any lasting effects. The billionaire will pay you one million dollars tomorrow morning if, at midnight tonight, you ''intend'' to drink the toxin tomorrow afternoon. He emphasizes that you need not drink the toxin to receive the money; in fact, the money will already be in your bank account hours before the time for drinking it arrives, if you succeed. All you have to do is ... intend at midnight tonight to drink the stuff tomorrow afternoon. You are perfectly free to change your mind after receiving the money and not drink the toxin.
A possible interpretation: Can you intend to drink the toxin if you also intend to change your mind at a later time?
The paradox
The paradoxical nature can be stated in many ways, which may be useful for understanding analysis proposed by philosophers:
* In line with
Newcomb's paradox
In philosophy and mathematics, Newcomb's paradox, also known as Newcomb's problem, is a thought experiment involving a game between two players, one of whom is able to predict the future.
Newcomb's paradox was created by William Newcomb of the ...
, an
omniscient
Omniscience () is the capacity to know everything. In Hinduism, Sikhism and the Abrahamic religions, this is an attribute of God. In Jainism, omniscience is an attribute that any individual can eventually attain. In Buddhism, there are diffe ...
pay-off mechanism makes a person's decision known to him before he makes the decision, but it is also assumed that the person may change his decision afterwards, of
free will
Free will is the capacity of agents to choose between different possible courses of action unimpeded.
Free will is closely linked to the concepts of moral responsibility, praise, culpability, sin, and other judgements which apply only to ac ...
.
* Similarly in line with Newcomb's paradox; Kavka's claim, that one cannot intend what one will not do, makes pay-off mechanism an example of
reverse causation.
* Pay-off for decision to drink the poison is ambiguous.
* There are two decisions for one event with different pay-offs.
Since the pain caused by the poison would be more than off-set by the money received, we can sketch the pay-off table as follows.
According to Kavka: Drinking the poison is never to your advantage regardless of whether you are paid. A rational person would know he would not drink the poison and thus could not intend to drink it.
David Gauthier
David Gauthier (; born 10 September 1932) is a Canadian-American philosopher best known for his neo-Hobbesian social contract (contractarian) theory of morality, as developed in his 1986 book ''Morals by Agreement''.
Life and career
Gauthie ...
argues once a person intends drinking the poison one cannot entertain ideas of not drinking it.
One of the central tenets of the puzzle is that for a reasonable person
* There is reasonable grounds for that person to intend to drink the toxin, since some reward may be obtained.
* Having come to the above conclusion there is no reasonable grounds for that person to drink the toxin, since no further reward may be obtained, and no reasonable person would partake in self-harm for no benefit.
Thus a reasonable person must intend to drink the toxin by the first argument, yet if that person intends to drink the toxin, he is being irrational by the second argument.
See also
*
Doublethink
Doublethink is a process of indoctrination in which subjects are expected to simultaneously accept two conflicting beliefs as truth, often at odds with their own memory or sense of reality. Doublethink is related to, but differs from, hypocrisy. ...
*
Prisoner's dilemma
The Prisoner's Dilemma is an example of a game analyzed in game theory. It is also a thought experiment that challenges two completely rational agents to a dilemma: cooperate with their partner for mutual reward, or betray their partner ("def ...
References
External links
Levy, Ken (2009). "On the Rationalist Solution to Gregory Kavka's Toxin Puzzle." Pacific Philosophical Quarterly 90, 267–289.
{{DEFAULTSORT:Kavka's Toxin Puzzle
Decision-making paradoxes
Puzzles
Thought experiments
Thought experiments in philosophy