Transcript Document

Critical Reasoning
Critical Reasoning
• Stephen Watson
– [email protected]
– Office in HSS 4234
– Consultations tba
Critical Reasoning
• Text
– R.J. Fogelin & W. Sinnott-Armstrong (2005)
7th edition Understanding Arguments: an
introduction to informal logic
Critical Reasoning
• Further Reading
– Cederblom, J. & D. W. Paulsen (c2001)
Critical Reasoning
– Copi, I. & C. Cohen, (1994), Introduction to
Logic
Critical Reasoning
• Assessment
– Mid-semester Assignment:
– Quiz #1 (week 7)
– Quiz #2 (week 12)
35%
30%
35%
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.
Critical Reasoning
• Lectures
– First part of 3 hour block is lectures
– Feel free to ask for clarifications during
lectures
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 you’re
understanding things at the time
Aspects of Language
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
Language and Argument
• An argument is the giving of reasons for or
against a claim.
• Arguing is a linguistic activity
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
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
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
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
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!"
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
Performatives
• Certain kinds of utterances —
performatives — bring something about,
rather than merely describe
– A marriage celebrant says
"You are now man and wife"
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 ... .
Explicit Performatives
• Examples
– "I now declare you man and wife"
– "I congratulate you"
• The saying is a kind of doing
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
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
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
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
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.).
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
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
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
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
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
Conversational Rules
• Cooperative conversations are governed
by such rules
• Hence, cooperative conversations are
situations in which conversational acts are
commonly performed
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
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
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
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
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 can’t be false)