Critical Reasoning

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Critical Reasoning
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Critical Reasoning

• Stephen Watson
• swatson_at_bond.edu.au
• Office in HSS 4234
• Consultations tba

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Critical Reasoning

• Text
• R.J. Fogelin W. Sinnott-Armstrong (2005) 7th
  edition Understanding Arguments an introduction
  to informal logic

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Critical Reasoning

• Further Reading
• Cederblom, J. D. W. Paulsen (c2001) Critical
  Reasoning
• Copi, I. C. Cohen, (1994), Introduction to Logic

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Critical Reasoning

• Assessment
• Mid-semester Assignment 35
• Quiz 1  (week 7) 30
• Quiz 2  (week 12) 35

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Critical Reasoning

• Goals
• improve critical reading skills required for
  undergraduate study
• improve academic writing skills and the clear
  presentation of your ideas
• assist in the imaginative aspects of thinking
  necessary to good problem solving.

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Critical Reasoning

• Lectures
• First part of 3 hour block is lectures
• Feel free to ask for clarifications during
  lectures

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Critical Reasoning

• Tutorials
• second part of 3 hour block is a tutorial
• Questions from the text or elsewhere will be
  discussed.
• Discussions will be on the material in the
  lecture just given so make sure youre
  understanding things at the time

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Aspects of Language
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• No man is an Island, entire of itself every man
  is a piece of the continent, a part of the main
  if a clod be washed away by the sea, Europe is
  the less, as well as if a promontory were, as
  well as if a manor of thy friends or of thine own
  were any man's death diminishes me, because I am
  involved in Mankind And therefore never send to
  know for whom the bell tolls it tolls for thee.
• John Donne

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Language and Argument

• An argument is the giving of reasons for or
  against a claim. 
• Arguing is a linguistic activity

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Language and Convention

• The language we use to communicate ideas,
  beliefs, etc. is a matter of convention.     
• semantic conventions words acquire their
  meaning by convention
• syntactic conventions grammar, is conventional

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Language and Convention

• Language is, however, not arbitrary .     
• Communication depends on shared linguistic
  conventions
• The truth or falsity of information communicated
  is generally not dependent on conventions

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Levels of Language

• Language can be used to perform many functions
• to convey or request information
• to bring things about
• to elicit a response in one's audience

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Linguistic Acts

• Language contains many conventions. Two have
  already been noted
• semantic conventions
• syntactic conventions
• When an utterance satisfies these two conventions
  we can be said to have performed a linguistic act

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Linguistic Acts

• Indicative mood (for a statement of fact)
• "He is running."
• Interrogative mood (for a question)
• "Is he running?"
• Imperative mood (for a command)
• "Run!"
• Expressive mood (for a desire or wish)
• "Ah, to be running now!"

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Speech Acts

• A linguistic act is one level at which speech
  acts can be described... but there is another
  level. The level of illocutionary acts

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Performatives

• Certain kinds of utterances performatives
  bring something about, rather than merely
  describe
• A marriage celebrant says
• "You are now man and wife"

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Explicit Performatives

• The Thereby Test
• Utterance U expresses an explicit performative
  just in case it
• (i) is first-person singular present
  indicative
• (ii) yields a true statement when plugged into
  the pattern In saying "I ..." I thereby ... .

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Explicit Performatives

• Examples
• "I now declare you man and wife"
• "I congratulate you"
• The saying is a kind of doing

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Kinds of Speech Acts

• Performative utterances are used for (linguistic
  acts and) speech acts
• One and the same linguistic act can do a variety
  of things perform a number of speech acts

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Kinds of Speech Acts

• Examples
• "Is there any pizza left?"                   
  "Yes"
• "Do you promise to pay me back?"  "Yes"
• "Do you swear to tell the truth?"       "Yes"
• "Do you refuse to leave?"                 "Yes"
• The linguistic act of saying "Yes" is used
• To state something
• To promise
• To take an oath
• To refuse

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Kinds of Speech Acts

• An illocutionary act is the act that an utterance
  effects.It is what is done in making the
  utterance.
• E.G. stating, promising, swearing, refusing

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Kinds of Speech Acts

• Different kinds of speech acts are named by the
  different verbs that occur in explicit
  performatives
• In saying "I promise ..." I thereby promise ...
• So promising is a kind of speech act
• In saying "I refuse to ..." I thereby refuse to
  ...
• So refusing is a kind of speech act.
• These verbs are called performative verbs

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Kinds of Speech Acts

• Not all speech acts are named by performative
  verbs
• The speech act of insulting is not.
• 'Insult' is not a performative verb.
• (Just try the thereby-test to see.).

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Making Statements

• One important kind of speech act is to make
  statements that are true or false
• the speech act of asserting, or stating, or
  describing

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Speech act rules

• To perform a particular speech act certain
  conventions may need to be met
• The speaker might need to occupy a special
  position
• Special words, gestures or formatting may be
  required
• There may be presupposed facts
• A particular response might be required

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Speech act rules

• Though a speech act may have occurred, it can be
  insincere
• Certain feelings or beliefs are expected by the
  speaker
• When you promise someone by saying "I promise"
  the speech act of     promising occurs, however
  it can be defective if the speaker is not sincere

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Perlocutionary Acts

• The act of causing an effect in an audience by
  means of language is a perlocutionary act
• "Look out for the tiger snake!"
• I perform the linguistic act of saying something
  meaningful
• I perform the illocutionary act of warning you
• I perform the perlocutionary act of putting you
  on guard

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Conversational Rules

• Linguistic acts can be used to perform
  perlocutionary acts because of assumed
  conventions or rules
• I say The house is on fire (linguistic act) and
  you are alerted (perlocutionary act) because we
  assume
• People generally aim at truth in cooperative
  conversation
• People generally have  evidence for claims they
  make

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Conversational Rules

• Cooperative conversations are governed by such
  rules
• Hence, cooperative conversations are situations
  in which conversational acts are commonly
  performed

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Conversational Implicature

• Because cooperative conversation is governed by
  rules we can draw conclusions from what someone
  says without them having to be explicitly stated
• "Where does Jo live? "
• "In Brisbane somewhere "
• Cooperative Rule  Be as informative as possible.
• Implicature I don't know exactly where Jo lives

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Conversational Implicature

• B conversationally implicated by linguistic act A
  just in case
• (i)  B is not explicitly stated by A(ii)  B
  could be false given A(iii) yet B could explain
  why A is uttered in a cooperative conversation

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Conversational Implicature

• Example
• "No one has spoken to Phil all evening"
• Conclude C No one likes Phil but
• It is not explicitly stated, and
• It could be false. But
• It explains why the remark was made

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Conversational Implicature

• Example
• "No one has spoken to Phil all evening"
• Conclude C No one likes Phil but
• It is not explicitly stated, and
• It could be false. But
• It explains why the remark was made
• So C is an implicature

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Conversational Implicature

• Compare
• "No one has spoken to Phil all evening"
• Conclude D Phil hasn't had a conversation all
  evening
• D is logically implied (it cant be false)