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Anticipating Objections in
Argumentation International Colloquium
on Rhetoric and Argumentation, Coimbra,
Portugal: Oct. 2, 2008.
Douglas Walton CRRAR
Centre for Research in
Reasoning, Argumentation &
Rhetoric: U. of Windsor
Proleptic Argumentation
 ‘Prolepsis’ [Greek prolambanein, to anticipate], has a
variety of meanings.
 One meaning is a figure of speech in which a future
event is referred to before it happens: “If you tell the
cops, you’re a dead man”.
 Another meaning is the anticipation and answering of
an objection or opposed argument before one’s
opponent has put it forward.
 ‘Proleptic argumentation’ in the sense used here
refers to any move in argumentation that contains an
anticipation and reply of this sort.
Importance of Anticipating
 If you are writing a proposal, and you have not
anticipated plausible objections, your argument is
likely to appear shallow and unpersuasive.
 The eloquence of the most eminent orators, such as
Demosthenes, Cicero, Burke and Lincoln, is based
on a dialectical sensibility marked by a welldeveloped capacity to recognize and counter
argumentative objections (Leff,1999, 510).
Global Warming (GW) Example
 Climate scientist Bruce, whose research is not
funded by industries that have financial interests at
stake, says that it is doubtful that climate change is
caused by carbon emissions.
 The argument anticipates and counters the objection
that Bruce’s research is biased, because it is funded
by industries that have financial interests at stake.
 The example is an instance of the argumentation
scheme for argument from expert opinion.
Argument from Expert Opinion
 Major Premise: Source E is an expert in domain D
containing proposition A.
 Minor Premise: E asserts that proposition A (in
domain D) is true (false).
 Conclusion: A may plausibly be taken to be true
(false).
The Global Warming Argument
 Premise: Bruce is an expert on climate science.
 Premise: Climate change is in the domain of climate
science.
 Premise: Bruce says that it is doubtful that climate
change is caused by carbon emissions.
 Conclusion: It is doubtful that climate change is
caused by carbon emissions.
Objection to the GW Argument
 Bruce’s research is funded by industries that have
financial interests at stake.
 Is Bruce biased?
 If Bruce is biased, he may not be a trustworthy
source.
 The original argument anticipates and replies to this
objection.
Linked or Convergent?
 In a linked argument, the premises function together
to support the conclusion.
 EXAMPLE: All men are mortal; Socrates is a man;
therefore Socrates is mortal.
 In a convergent argument, each premise provides
independent support for the conclusion.
 EXAMPLE: Tipping is a bad practice. For one thing, it
makes the party receiving the tip feel undignified. For
another thing, it leads to an underground, blackmarket economy.
The GW Argument as Linked
Bruce is an
expert on
climate change.
Bruce says it is doubtful
that climate change is
caused by carbon
emissions.
Argument from Expert Opinion
It is doubtful that climate change is
caused by carbon emissions.
Bruce’s research is
not funded by
industries that have
financial interests at
stake.
The GW Argument as Convergent
Bruce is an
expert on
climate change.
Bruce says it is doubtful
that climate change is
caused by carbon
emissions.
Argument from Expert
Opinion
It is doubtful that climate change
is caused by carbon emissions.
Bruce’s research is
not funded by
industries that have
financial interests at
stake.
Another Way to See It
 We could see the GW argument as proleptic because
it anticipates a critical question, and provides an
answer to it in advance.
 If his research is funded by industries that have
financial interests at stake, this raises questions
about his reliability as an expert source who can be
trusted to be obective.
Critical Questions (Walton, 1997, 223)






Expertise Question: How knowledgeable is E as an
expert source?
Field Question: Is E an expert in the field D that A is
in?
Opinion Question: What did E assert that implies A?
Trustworthiness Question: Is E personally reliable
as a source?
Consistency Question: Is A consistent with what
other experts assert?
Backup Evidence Question: Is E’s assertion based
on evidence?
Trustworthiness Question Anticipated
 It answers the trustworthiness question by rebutting
the suspicion that Bruce might be biased.
 His research might be funded by industries that have
financial interests at stake.
 If so, he would be biased.
 If he is biased, he is not personally reliable as a
source. the trustworthiness critical question is raised.
The Scientific Truth Example
Sharon Begley, ‘The Truth about Denial’,Newsweek, Aug. 13, 2007

This argument cited was put forward by advocates of global warming, in
response to arguments of their critics portraying scientific opinion as divided.
The critics cited a petition signed by over 100 scientists and others, including TV
weathermen, who had said that they cannot subscribe to the view of global
warming that claims it causes climate catastrophes.
 Scientific truth is not decided by majority vote, of course (ask
Galileo), but the number of researchers whose empirical studies
find that the world is warming and that human activity is partly
responsible numbered in the thousands even then. The IPCC
report issued this year, for instance, was written by more than
800 climate researchers and vetted by 2,500 scientists from 130
nations.

The Inter-governmental Panel on Climate Change (IPCC) is an international
body that periodically assesses climate research.
Argument from Expert Opinion
 The IPCC report supports the hypothesis of global
warming.
 The IPCC report was written and vetted by scientists
who are experts.
 Therefore the hypothesis of global warming is
plausible.
Objection
 There was a petition signed by over 100 scientists
and others, including TV weathermen who said they
do not accept the hypothesis of global warming.
 Therefore scientific opinion on global warming is
divided [i.e. the experts disagree].
 If the experts disagree, that finding casts the
hypothesis of global warming into doubt.
 Therefore, there is reasonable doubt concerning the
hypothesis of global warming.
Reply to Objection
 The numbers are impressive. The IPCC report
endorsing the hypothesis of global warming was
written by more than 800 climate researchers and
vetted by 2,500 scientists from 130 nations.
 Acceptance by a such an impressive number of
scientists supports the hypothesis of global warming,
even if some scientists do not accept it.
 Therefore the hypothesis of global warming is
plausible even though there may be some grounds for
doubt about it.
Objection to Reply to Objection
 Scientific truth is not decided by majority vote.
 In the case of Galileo, the majority was against
scientific truth.
 If scientific truth is decided by majority vote, the
argument becomes merely a numbers game of how
many scientists are for or against.
 If so, the argument would be merely an appeal to
majority opinion (ad populum) rather than an appeal
to expert opinion.
Reply to Objection
 This is more than an ad populum argument from a
majority of scientists.
 The numbers suggest that the opinion that the world
is warming is the accepted scientific opinion among
scientists from many nations.
 This convergence of acceptance casts doubt on the
objection that scientific opinion on global warming is
divided.
The Example as a Dialog
 There are two sides, the global warming skeptics and
the global warming advocates.
 The argument was originally put forward by the
advocates to attack the prior argument of the skeptics
that scientific on the global warning issue is divided.
 It cited large numbers of scientific experts on the side
of the global warming hypothesis.
 But it also rebutted the possible counter-argument
that could be put forward next by the skeptics that
their makes it into a popularity contest.
Poisoning the Well
 Democratic capitalism is the best system of
government, because anyone who is against it is a
communist who has no regard for the truth of any
matter being discussed.
 This kind of argumentation in the fallacies literature is
called “poisoning the well”.
 It is proleptic because it anticipates objections and
rebuts them in advance of any reply.
What is an Argument?
 An argument is a move composed of premises and a
conclusion used to fulfill a goal in a dialog with two
sides (Walton and Krabbe, 1995).
 A side wins if it puts forward arguments that prove the
proposition that is its ultimate probandum.
 Each single argument is put forward by one party to
try to get the other party to accept a conclusion that
can be used to move ahead, one step at a time, in a
chain of argumentation that proves its ultimate
probandum.
Simple Dialog Systems
 Multiple-move dialogs are possible (Walton and




Krabbe, 1995), but the following rule applies to what
might be called single-move (simple) dialogs.
In a simple dialog, a party can make only make one
move (speech act) at his/her turn (move).
For example, a party can put forward an argument,
but only one, in a simple dialog.
Replying to an objection to one’s argument is a
different move from putting forward the argument.
On these assumptions, it follows that proleptic
argumentation is not allowed in simple dialogs.
The Primary Method
 1. Fill in any ordinary premises that might not be
explicitly stated in the given argument.
 2. Scan over the standard critical questions matching
that scheme, and judge which one is most powerful
as a potential objection, from what is known of the
context of the dialog.
 3. Build in an additional premise to the argument that
anticipates this objection and rebuts it.
 4. Build in any other premises needed to help provide
the new argument for the rebuttal.
The Secondary Method
 1. Go through the list of common counter-arguments
used to attack this particular type of argument.
 2. Examine each of these counter-arguments in light
of the context of the debate to see if one might fit.
 3. If you find one that fits, anticipate the objection by
building in a premise stating that this particular type
of counter-argument does not apply.
 4. Give an argument supporting the premise, for
instance by citing an example that shows why this
particular type of counter- argument does not apply.
References
 Michael Leff, ‘Rhetorical Prolepsis and the Dialectical
Tier of Argumentation’, Proceedings of the Fourth
ISSA Conference, ed. Frans H. van Eemeren et al.,
Amsterdam, SIC SAT, 1999, 510-513.
 Douglas Walton, Appeal to Expert Opinion, University
Park, Penn State Press, 1997.
 Douglas Walton and Erik C. W. Krabbe, Commitment
in Dialogue, Albany, State University of New York
Press, 1995.
 Douglas Walton, Chris Reed and Fabrizio Macagno,
Argumentation Schemes, Cambridge, Cambridge
University Press, 2008.