Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logic
Paweł Łozinski
http://www.ii.pw.edu.pl/∼plozinsk
Institute of Computer ScienceFaculty of Electronics and Information Technology
Warsaw University of Technology
17 March 2009
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Ancient Greece – logic
Questions that brought logic into being:
How do we reason?
How do we justify our convictions (what makes a good/bad justification)?
Focus on reasoning itself, not things we reason about.
Sylogism
(. . . ) discourse in which, certain things being stated, something other than what
is stated follows of necessity from their being so.a
aAristotle. Prior analytics, par. 100b; Topics, par. 24a.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Ancient Greece – logic
Questions that brought logic into being:
How do we reason?
How do we justify our convictions (what makes a good/bad justification)?
Focus on reasoning itself, not things we reason about.
Sylogism
(. . . ) discourse in which, certain things being stated, something other than what
is stated follows of necessity from their being so.a
aAristotle. Prior analytics, par. 100b; Topics, par. 24a.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Ancient Greece – logic
Questions that brought logic into being:
How do we reason?
How do we justify our convictions (what makes a good/bad justification)?
Focus on reasoning itself, not things we reason about.
Sylogism
(. . . ) discourse in which, certain things being stated, something other than what
is stated follows of necessity from their being so.a
aAristotle. Prior analytics, par. 100b; Topics, par. 24a.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
19th century – formal logic
Characteristic features:
1 Focus on infaliablity of reasoning (deduction).
2 Subject independence.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
19th century – formal logic
Characteristic features:
1 Focus on infaliablity of reasoning (deduction).
2 Subject independence.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logic – early fundations
Stephen Toulmin. The uses of argument. 1958.
Arthur Hastings. A reformulation of the modes of reasoning in
argumentation. 1963.
Charles Hamblin. Fallacies. 1970.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logicBack to the question: How do we reason?
Sample bases for reasoning:
“John says chances for rain are about 75%”;
“Allowing stem cell research is playing God”;
“Polish economy will develop similarly to Irish economy few years earlier”.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logicBack to the question: How do we reason?
Sample bases for reasoning:
“John says chances for rain are about 75%”;
“Allowing stem cell research is playing God”;
“Polish economy will develop similarly to Irish economy few years earlier”.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logicBack to the question: How do we reason?
Sample bases for reasoning:
“John says chances for rain are about 75%”;
“Allowing stem cell research is playing God”;
“Polish economy will develop similarly to Irish economy few years earlier”.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logic – main features
Uncertainty:
we cannot guaranty that claim inferred from true premises will be true;
we cannot guaranty that claims thought to be true won’t be falsified when
new facts arrive.
Language dependance: validity of our reasoning depends on the words we
use to express it.
Dialogue:
a method for deciding whether a claim is true or false;
a context for evaluation of our inferences.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logic – main features
Uncertainty:
we cannot guaranty that claim inferred from true premises will be true;
we cannot guaranty that claims thought to be true won’t be falsified when
new facts arrive.
Language dependance: validity of our reasoning depends on the words we
use to express it.
Dialogue:
a method for deciding whether a claim is true or false;
a context for evaluation of our inferences.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logic – main features
Uncertainty:
we cannot guaranty that claim inferred from true premises will be true;
we cannot guaranty that claims thought to be true won’t be falsified when
new facts arrive.
Language dependance: validity of our reasoning depends on the words we
use to express it.
Dialogue:
a method for deciding whether a claim is true or false;
a context for evaluation of our inferences.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Informal logic – main features
Uncertainty:
we cannot guaranty that claim inferred from true premises will be true;
we cannot guaranty that claims thought to be true won’t be falsified when
new facts arrive.
Language dependance: validity of our reasoning depends on the words we
use to express it.
Dialogue:
a method for deciding whether a claim is true or false;
a context for evaluation of our inferences.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
General inference pattern
premise1,premise2, . . . ,premisenrule of inference−−−−−−−−→ conclusion,
We claim the conclusion to be true on the bases of our inference.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Claim
Claims can be contradictory on 4 different levels:
1 level of fact,
2 level of definition,
3 level of value,
4 level of policy.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Claim
Claims can be contradictory on 4 different levels:
1 level of fact,
2 level of definition,
3 level of value,
4 level of policy.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Claim
Claims can be contradictory on 4 different levels:
1 level of fact,
2 level of definition,
3 level of value,
4 level of policy.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Claim
Claims can be contradictory on 4 different levels:
1 level of fact,
2 level of definition,
3 level of value,
4 level of policy.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Premises
Definition (Premise)
Premise is data that critical audiences generally accept.
What can be a premise?
Objective data – statistics, experiment results, items (e.g. in a court case);
generally accepted claims;
an opinion of a credible person (competent, trustworthy, good will,
dynamic);
claims supported by other, valid arguments.
Fact
Irrefutable premises practically don’t exist.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Premises
Definition (Premise)
Premise is data that critical audiences generally accept.
What can be a premise?
Objective data – statistics, experiment results, items (e.g. in a court case);
generally accepted claims;
an opinion of a credible person (competent, trustworthy, good will,
dynamic);
claims supported by other, valid arguments.
Fact
Irrefutable premises practically don’t exist.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Premises
Definition (Premise)
Premise is data that critical audiences generally accept.
What can be a premise?
Objective data – statistics, experiment results, items (e.g. in a court case);
generally accepted claims;
an opinion of a credible person (competent, trustworthy, good will,
dynamic);
claims supported by other, valid arguments.
Fact
Irrefutable premises practically don’t exist.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Premises
Definition (Premise)
Premise is data that critical audiences generally accept.
What can be a premise?
Objective data – statistics, experiment results, items (e.g. in a court case);
generally accepted claims;
an opinion of a credible person (competent, trustworthy, good will,
dynamic);
claims supported by other, valid arguments.
Fact
Irrefutable premises practically don’t exist.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Premises
Definition (Premise)
Premise is data that critical audiences generally accept.
What can be a premise?
Objective data – statistics, experiment results, items (e.g. in a court case);
generally accepted claims;
an opinion of a credible person (competent, trustworthy, good will,
dynamic);
claims supported by other, valid arguments.
Fact
Irrefutable premises practically don’t exist.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Premises
Definition (Premise)
Premise is data that critical audiences generally accept.
What can be a premise?
Objective data – statistics, experiment results, items (e.g. in a court case);
generally accepted claims;
an opinion of a credible person (competent, trustworthy, good will,
dynamic);
claims supported by other, valid arguments.
Fact
Irrefutable premises practically don’t exist.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Rules of inferenceBack to question: How do we justify our convictions?
Definition (Argumentation scheme)
Argumentation schemes are forms of argument that capture stereo-
typical patterns of human reasoning, especially defeasible ones like
argument from expert opinion, that have proved troublesome to view
deductively or inductively.a
aD. Walton. Justification of argumentation schemes. 2005.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Argumentation schemesClassification(s)
Argument from generalization,
Argument form causal relation,
Argument form expert opinion,
Argument from sign,
Argument from analogy,
. . . . . . ..
. . . .
..
.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Argumentation schemes
Example
Premises:
(a) John is not looking me in the eyes when he talks about smth.
(b) Generally, avoiding eye contact is a sign of insincerity.
Conclusion: John is lying.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Argumentation schemesCritical questions
Argument from sign
Premises:
(a) A is true in this situation.
(b) Event B is generally indicated as true when its sign, A, is true in this kind of
situation.
Conclusion: B is true in this situation.
Critical questionsa
1 What is the strength of the correlation between A and B?
2 Do we (currently) know of any events other than B that would more
reliably account for A?
aArthur Hastings. A reformulation of the modes of reasoning in argumentation. 1963.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Argumentation schemesCritical questions
Argument from sign
Premises:
(a) A is true in this situation.
(b) Event B is generally indicated as true when its sign, A, is true in this kind of
situation.
Conclusion: B is true in this situation.
Critical questionsa
1 What is the strength of the correlation between A and B?
2 Do we (currently) know of any events other than B that would more
reliably account for A?
aArthur Hastings. A reformulation of the modes of reasoning in argumentation. 1963.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
ClaimPremisesRules of inference
Argumentation schemesCritical questions
Argument from sign
Premises:
(a) A is true in this situation.
(b) Event B is generally indicated as true when its sign, A, is true in this kind of
situation.
Conclusion: B is true in this situation.
Critical questionsa
1 What is the strength of the correlation between A and B?
2 Do we (currently) know of any events other than B that would more
reliably account for A?
aArthur Hastings. A reformulation of the modes of reasoning in argumentation. 1963.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Problem
Fact
People face conficts of:
opinions (what is morally right/what to do/what is the state of
matters/. . . ),
interests.
Fact
All we have are uncertain and context dependant arguments.
Question
How do we resolve those conflicts?
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Problem
Fact
People face conficts of:
opinions (what is morally right/what to do/what is the state of
matters/. . . ),
interests.
Fact
All we have are uncertain and context dependant arguments.
Question
How do we resolve those conflicts?
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Problem
Fact
People face conficts of:
opinions (what is morally right/what to do/what is the state of
matters/. . . ),
interests.
Fact
All we have are uncertain and context dependant arguments.
Question
How do we resolve those conflicts?
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Solution
Answer
By testing our claims through process of questions and answers.
Definition (Dialogue)
Dialogue is a multilateral process of reaching a goal (often to resolve a conflict)
through exchange of locutions.
Examples of dialogues:
everyday discourse,
teacher–student dialogue,
court trials,
Plato’s dialogues.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Solution
Answer
By testing our claims through process of questions and answers.
Definition (Dialogue)
Dialogue is a multilateral process of reaching a goal (often to resolve a conflict)
through exchange of locutions.
Examples of dialogues:
everyday discourse,
teacher–student dialogue,
court trials,
Plato’s dialogues.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Solution
Answer
By testing our claims through process of questions and answers.
Definition (Dialogue)
Dialogue is a multilateral process of reaching a goal (often to resolve a conflict)
through exchange of locutions.
Examples of dialogues:
everyday discourse,
teacher–student dialogue,
court trials,
Plato’s dialogues.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Fundamental concepts
Presumption/burden of proof,
burden of rejoinder,
commitments.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Fundamental concepts
Presumption/burden of proof,
burden of rejoinder,
commitments.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Fundamental concepts
Presumption/burden of proof,
burden of rejoinder,
commitments.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Dialogue stages
1 Opening stage (specification of the type and rules of the dialogue):
locution rules,dialogue rules,commitment rules,win-loss rules;
2 confrontation stage (pinpointing the conflict);
3 argumentation stage (the main part...);
4 closing stage (deciding what is the outcome of the dialogue).
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Dialogue stages
1 Opening stage (specification of the type and rules of the dialogue):
locution rules,dialogue rules,commitment rules,win-loss rules;
2 confrontation stage (pinpointing the conflict);
3 argumentation stage (the main part...);
4 closing stage (deciding what is the outcome of the dialogue).
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Dialogue stages
1 Opening stage (specification of the type and rules of the dialogue):
locution rules,dialogue rules,commitment rules,win-loss rules;
2 confrontation stage (pinpointing the conflict);
3 argumentation stage (the main part...);
4 closing stage (deciding what is the outcome of the dialogue).
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Dialogue stages
1 Opening stage (specification of the type and rules of the dialogue):
locution rules,dialogue rules,commitment rules,win-loss rules;
2 confrontation stage (pinpointing the conflict);
3 argumentation stage (the main part...);
4 closing stage (deciding what is the outcome of the dialogue).
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Dialogue stages
1 Opening stage (specification of the type and rules of the dialogue):
locution rules,dialogue rules,commitment rules,win-loss rules;
2 confrontation stage (pinpointing the conflict);
3 argumentation stage (the main part...);
4 closing stage (deciding what is the outcome of the dialogue).
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Dialogue stages
1 Opening stage (specification of the type and rules of the dialogue):
locution rules,dialogue rules,commitment rules,win-loss rules;
2 confrontation stage (pinpointing the conflict);
3 argumentation stage (the main part...);
4 closing stage (deciding what is the outcome of the dialogue).
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Dialogue stages
1 Opening stage (specification of the type and rules of the dialogue):
locution rules,dialogue rules,commitment rules,win-loss rules;
2 confrontation stage (pinpointing the conflict);
3 argumentation stage (the main part...);
4 closing stage (deciding what is the outcome of the dialogue).
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
“Justification”Fundamental conceptsDialogue stages
Dialogue stages
1 Opening stage (specification of the type and rules of the dialogue):
locution rules,dialogue rules,commitment rules,win-loss rules;
2 confrontation stage (pinpointing the conflict);
3 argumentation stage (the main part...);
4 closing stage (deciding what is the outcome of the dialogue).
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
FallaciesBack to question: What makes a good/bad justification?
Argument ad hominem (personal attack),
Argument ad baculum (resorting to force),
Argument ad verecundiam (bad usage of an argument from expert’s
opinion),
. . . .
..
.
Fact
Generally, you can find situations in which the above are not fallacious
arguments.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Some developments – argumentationSome developments – dialogue
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Some developments – argumentationSome developments – dialogue
Goals
1 Creating formal models helps us to understand the thing that we try to
formalise.
2 Formal models can be implemented.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Some developments – argumentationSome developments – dialogue
Goals
1 Creating formal models helps us to understand the thing that we try to
formalise.
2 Formal models can be implemented.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Some developments – argumentationSome developments – dialogue
Dung’s Argumentation Framework
P. M. Dung. On the acceptability of arguments. . . . 1995.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Some developments – argumentationSome developments – dialogue
Carneades Argumentation Framework
T. Gordon, D. Walton. The Carneades Argumentation Framework. 2006.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Some developments – argumentationSome developments – dialogue
Prakken’s Framework
H. Prakken. Coherence and Flexibility in Dialogue Games for Argumentation.
2005.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Agenda
1 Historical background
2 Argument
Claim
Premises
Rules of inference
3 Dialogue
“Justification”
Fundamental concepts
Dialogue stages
4 Fallacies5 Attempts of informal logic formalisation
Some developments – argumentation
Some developments – dialogue
6 ConclusionsPaweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Conclusions
Informal logic aims at describing the human way of reasoning:
arguments are defeasible inferences of the form
premisesarg.scheme−−−−−→ claim,
where not only the premises, but also the application of argumentation
scheme must be justifiable.
dialogue is a method for evaluation of claims and arguments that support
them.
There are promising (yet early) attempts of formal applications of informal logic.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Conclusions
Informal logic aims at describing the human way of reasoning:
arguments are defeasible inferences of the form
premisesarg.scheme−−−−−→ claim,
where not only the premises, but also the application of argumentation
scheme must be justifiable.
dialogue is a method for evaluation of claims and arguments that support
them.
There are promising (yet early) attempts of formal applications of informal logic.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic
Historical backgroundArgumentDialogueFallacies
Attempts of informal logic formalisationConclusions
Thank you
. . . for your attention.
Paweł Łozinski http://www.ii.pw.edu.pl/∼plozinsk Informal logic