24 September 2011
What is an argument?
A product (book, essay, editorial, etc).
A process (dialectical) - (Carl Marx) one side of argument and criticism, counter-criticism.
Instrument used for “rational” persuasion (vs. bribe, force, charm, intimidate, etc).
A set of claims / statements (at least two) that must be related.
At least one claim is used to support another claim.
eg. [ She’s armed ]. So, [ she’s dangerous ].
Not an argument because one claim does not support the other claim.
eg. The lights are on in this room. The clock at the front of the class has stopped.
So, therefore, thus
claim = premise (supporting claim) Make an “inference.” = Making an intuitive connection. Is the inference “warranted?”
claim = conclusion, point that is trying to be justified / proved.
Evaluate argument at the level of claim. True / falsity of supporting claim.
Not disputing evidence but disputing the inference.
How can we tell how a claim is meant to be used?
Sometimes by context in which a discussion or debate is going on, the intention of the
speaker, or indicator words that indicate premises or conclusions.
Whatever follows is the reason for
ex. He’s going to do well [ because ] he’s committed to it.
because, since, for, seeing that, as, given that, considering that
therefore, so, thus, consequently, it follows that
What is not a claim?
Question* - eg. what time is it?
exception: loaded questions are claims (the claim is inside the question.) rhetorical
questions. eg. when will the gov end its failed policies.
Command* - eg. shut the door exception: can be an “ought” imperative - eg. [ shut the door ] you ought to shut the door,
there’s a lion outside.
Request - eg. please do something.
Proposal - eg. let’s get married.
Exclaimation - eg. oh my goodness!
What is not an argument?
Report - describes a situation, does not try to prove anything.
Unsupported assertion - a claim lacking support, an opinion (subjective preference).
Conditional statements - “if ... then ...” statements.
Illustrations - used to clarify a point but not to prove it. Examples are used to clarify a point,
examples are used to prove a point in arguments.
Explanation - tells us how or why something is the case, does not try to prove that something is
Types of support (premises)
Independent - premise works by itself to prove a conclusion
Linked - one premise needs another premise (to be relevant) to prove a conclusion. Without
linked premises, a premise does not prove a conclusion.
1 October 2011
Missing Premises & Conclusions
eg. The bigger the burger, the better the burger. The burgers are bigger at Burger King.
implicit conclusion: is that the burgers are better at Burger King.
Not stated but assumed. It is part of the argument but it’s missing.
eg. Herman couldn’t be the person who robbed the store [ because ] he did not have a tattoo.
Hidden Premise: The robber had a tattoo on his left arm.
Premise: He didn’t have a tattoo on his left arm.
Conclusion: Herman couldn’t be the person who robbed the store.
Simple vs Complex Arguments
Simple arguments have only one conclusion, eg: She’s armed so she’s dangerous.
Complex arguments has multiple conclusions. Standard form:
Supporting Premise / Conclusion (Premise that supports the conclusion)
Diagram form: P1, P2, P3 = C1
Now look, (1) everyone who has read Marx knows that capitalism can’t survive into the 21st
century and (2) Sanchez has read more than his share of Marx. So, (3) he is well aware of that.
And if he’s well aware of that, (4) he’s lying to you when he says you should start a florist shop.
(5) The man’s a liar.
Linked premises: 1+2 proves 3 which proves 4 which proves 5
(1) Everyone who has read Marx knows that capitalism can’t survive into the 21st century.
(2) Sanchez has read more than his share of Marx.
(3) He’s well aware that capitalism can’t survive into the 21st century. (1+2)
(4) He’s lying to you when he says you should start a florist shop. (3)
Main conclusion: (5) The man’s a liar. (3, 4)
15 TF = Chapter 1 & 2
10 MC = Chapter 1, some of 2
5 passages (just like homework - what’s premise and conclusion, possibility not an arguments in
which case explain why it’s not)
pages 1 to 52, 180 to 181, 164 to 170
One question on test that will require bracketing a phrase and do standard form and diagram
15 October 2011
Two Types of Reasoning
1) Form > Structure > Syllogism
2) Content > Subject
- Conclusions are necessary
- Logic is 100% or not Non-Deductive
- Conclusions are only probable
- Arguments are weaker or stronger by degree
Valid Forms of Deductive Logic
(MP) Modus Ponens
If P (antecedent), then Q (consequent)
P - affirming the antecedent
(MT) Modus Tollens
not Q - denying the consequent
So, not P
Either A or B (disjunt) , the word “or” is used exclusively.
Argument by Elimination
Not A Not B
So, B So, A
A (affirming the disjunt)
So, not B
22 October 2011
More Valid Forms
If P, then Q
If Q, then R
If P, then R
All men (A) are mortal (B) < major premise Socrates (C) is a man (A) < minor premise
Socrates (C) is mortal (B) < conclusion
Latecomers (S) should be applauded (P) < value premise
William (Q) is a latecomer (S) < factual premise
William (Q) should be Applauded (P) < value conclusion
Invalid Forms of Logic
1) Affirming the consequent
If it’s red (P), then it’s a colour (Q).
It’s a colour (Q)
So, it’s red (P)
2) Denying the Antecedent
If it rains (P), then there are clouds (Q).
It is not raining (P)
So, there are no clouds (Q)
3) Affirming the inclusive disjunt
The word “or” is used inclusively.
Either the person’s a man (A) or a Canadian (B).
The person is a man (A)
So, the person cannot be Canadian (B)
But one can be both, a Canadian and a man.
4) The fallacy of common antecedent
If I smoke (P), then I’ll be cool (Q)
If I smoke (P), then I’ll get cancer (R)
So, If I will be cool (Q) then I will get cancer (R)
5) The fallacy of common consequent If it’s red (P), then it’s a colour (R)
If it’s green (Q), then it’s a colour (R)
If it’s red (P), then it’s green (Q)
6) Incorrect Categorical Syllogism
All cats (A) animals (B)
All dogs (C) are animals (B)
So, all cats (A) are dogs (C)
29 October 2011
Test Nov 12th
- 5 passages - express dedutive form (if P than Q, P / So, Q), naming, valid / invalid, bracketing
(A, B, C, etc)
- 10 identifying claims
- non-deductive, reasoning
- Different types of arguments use different types of criteria for evaluation.
Truth: Claims are either true or false (acceptable or not).
Validity: Form of argument is either 100% valid or invalid.
Soundness: True claims and valid in form.
2) Non-deductive (inductive)
Truth, Strength, Cogency
Weak arguments are always uncogent.
Strong arguments can be cogent or uncogent.
Common Patterns of Non-deductive Reasoning
1) Inductive Generalization
- Different from a generalization.
- What’s generally “true” for most or all.
- A claim made about an “entire population” based on a sample of that population. - A good inductive generalization must be based on a sample that is large enough and
representative of the entire population.
2) Predictive Argument
- A prediction is supported with reasons.
3) Argument from Authority
- A claim or conclusion is supported by an appeal to authority.
4) Causal Argument
5) Statistical Argument
6) Argument from Analogy
5 November 2011
Evaluating Claims within an Argument
The strength of an argument depends on the relevance, acceptability, and the sufficiency of the
Irrelevance - the truth or falsity of the claim has no bearing on the conclusion.
Positive Relevance - a claim lends weight (supports) to a conclusion and makes the conclusion
more likely (more justified). Warrants the inference.
Negative Relevance - makes the conclusion less likely and makes the argument weaker.
Fallacy of Irrelevant Premise
Irrelevant claims don’t warrant the conclusion.
Claims are either acceptable or not / true or false / justifiable or not.
Different kinds of claims require different procedures of evaluation.
Unacceptable claims weakens the arguments. Relevant acceptable claims strengthens the
Sufficiency Sometimes as little as one claim can prove the conclusion.
Ask: is there enough to prove / warrant / justify the conclusion.
If so, the argument succeeds.
Types of Claims
Factual claims - can be true or false. (generalization, causal claims)
- “is” / was / will be the case.
- Verification (physical evidence, inference drawn from an observation, experiment,
appeal to authority)
- Good or evil, better or worse, out imperatives.
- Justification (appeal to principles and values such as fairness, justice, etc).
Four Tests to Evaluate Normative Claims
1) Role-Exchange - take a rule of behaviour and apply it to yourself. If you wouldn’t
accept it applied to yourself, then the principle is unacceptable.
2) New Cases - use new cases to test the principles.
3) Higher Order Principle - specific principles are justified by appeal to higher order
4) Consistency in Universalizability - principle must be consistent.
Claims are acceptable or not depending on the meaning or the language used.
- Language can be too vague, narrow, broad, etc.
- Definitions must be clear.
- Conceptual analysis
7 January 2012
Paper topic: Is capitalism democratic?
Is pornography hate literature? Techniques of Conceptual Analysis
1. Model Case: - Answer YES to the question.
- Produce an example which illustrates this.
A white supremacy group publishes stories and photo stills from their snuff films. In
these films, non-white women are abducted, molested, raped, killed, and dismembered.
This publication is distributed to other clan members for purposes of sexually exciting
PORNOGRAPHY HATE LITERATURE
- The powerful take sexual advantage of - People of a particular race are degraded.
woman of colour. - Used by the powerful to suppress the weak.
- Can involve group sex. - Distinguishes between the in and out
- Portray group stereotypes. groups.
- Is distributed by publishers. - Is distributed by underground organizations.
2. Contrary Case: - Answer NO to the question.
- Produce an example which illustrates this.
A married couple is experiencing sexual problems. They go to a sex therapist for help.
The therapist gives them a copy of playboy, kama sutra, and other “how-to” sex
manuals. She gives the couple homework assignments requiring experimentation-risk-
PORNOGRAPHY HATE LITERATURE WHAT’S MISSING? (WHY IS
THERE NO HATE?)
- Can be shared. - An expression of anger or - No anger or negativity.
- Has therapeutic or healing negativity towards others. - No group is targeted.