What follows are the generally unedited and
uncorrected student notes of the class. It may provide a guide
for what was covered in class. Caveat lector.
September 12,
2012 Marty
Cashen
Please read
the Apology page 423 in your Plato book, we could start going
over this next week.
Logic is the
study of reason and argument, rational persuasion of a person.
An argument is
any conversation were you are trying to persuade someone to
believe your conclusion by using premises.
Premises are
reasons to support your conclusion; they are used to help you
persuade someone your conclusion.
A discourse
can be defined as a connected series of statements.
When reading a
connected series of statements (discourse), to be an argument
you do not want to EXPLAIN things, you still need to persuade
the person.
Not all
discourses are argument, but sometimes the argument could be
hidden in a story.
When engaged
in an argument or reading one, you need to look and see is
this person trying to convince me of something. Are they
trying to persuade me enough to believe their conclusion?
To help you
determine an argument, look for indicator words. Indicator
words are works that lead you up to something. There are two
types of indicator words premises and conclusion words.
Premises
indicators are letting you know that a reason is coming up.
Examples of premises words are because, since, moreover,
furthermore, etc.
Conclusion
indicators are letting you know that a conclusion is coming
up. Examples of conclusion words would be, so, hence,
therefore, thus, consequently, etc.
Sometimes they
give you false reason, meaning they give you indicator words
but it still isn’t an argument.
EX- I punched
John because he insulted my mother.
This is not an
argument even though it has a premises indicator (because).
This statement is not trying to persuade you of anything, it’s
just a fact.
There are two
ways to help you determine an argument.
1)Is the purpose of
the discourse trying to persuade me?
2)The usage of
indicator words.
Good arguments have to be reasonable to accept, you can use
three distinct terms to help you.
1)Is the argument
logically strong?
2)Is the argument
valid?
3)Is the argument
sound?
Logically
sound means any argument were the
premises gives you some good reason to believe the conclusion.
A valid
argument is if the premises are TRUE, then the conclusion must
be TRUE.
An example of
a valid argument would be.
Antigonish is
in NS
NS is in
Canada
Antigonish is
in Canada.
We will learn
about sound arguments in the next class.
THERE WILL BE
A QUIZ ON FRIDAY FOR THE FIRST 10 MINUTES OF CLASS.
Aaron Doucette / [to come?]
Friday 21st of September (David Feehan)
Statement
Form.
1.Simple
Statement-
one simple statement
•The Cat is on the mat
2.Negation-
One
Statement
•Its not true that the cat
is on the mat
3.Conjunction-joins
two
simple statements, both statements must be true if the statement
is true
•the cat is on the mat and
its purring
4.Disjunction
Inclusive-
One of the statements can be true but both can be as well
•Either the cat is on the
mat, or its on the table
5.Disjunction Exclusive-
Only one can be correct and the other must be wrong. The truth
of one, excludes the other.
6.Conditional
or
Hypothetical- “Don’t worry about that now”
•If the cat is on the mat,
then let sleeping cats lie.
Necessary
Truth and Contradiction (Necessarily False)
•If “P” then “P” ( as long
as P is the same thing) then it must be true
•Two Negations can cancel
each other out
If I’m Will Sweet then I’m Will Sweet. -True
If it is false that i am not Will Sweet then i am
Will Sweet-True
Either i am Will Sweet or I’m not Will Sweet-True
I am Will Sweet- False
All unmarried women are spinsters- True
All swans are white- False
Mon Sept 24 (Libby Hughes)
Necessary Truth and
Contradiction
A contradiction is necessary false
Necessary truth is absolutely true
Necessarily true structure:
If “P” then “P”
If not not “P” then “P”
Either “P” or not “P”
Contingent – something happens to be true,
most sentences are contingent.
A statement can be not necessarily true, if
it is true for one person and not for another. Example - my name
is Libby. This is true for me but not for others.
The structure of a statement doesn’t always
indicate that it is necessarily true or false. It is about the
content of the statement and what the words mean – analysis.
Statements can be analytically true or true by definition,
looking at the content. If you know the concepts of the content
is true, then it is true by definition.
A statement is a necessary truth if the truth
can be known on purely logical grounds.
Structure/form = tautology (must be true)
Example
God is all powerful
This is necessarily false as there is no
possible way that it can be true
Consistency and
Inconsistency
Example
All human beings have rights vs Some human
beings do not have rights -
This is inconsistent
Consistency - it is possible that both
sentences are true at the same time.
There is a possible situation in which all
statements are true
If sentences do not contradict each other
then they are consistent.
Example
Consistent -
She is wearing blue
She is wearing red
Inconsistent –
She is wearing only blue
She is wearing red
September 26, 2012
(Christopher Keeping)
Introduction
We took the
majority of the class to review the material that we covered
in the last couple of weeks, below are my interpretations
about the material covered in class.
Material
Formal Logic – This deals with the
structure of an argument’s conclusion and its premises.It can be in other
language systems for example 1 + 1 = 2 would use formal logic
with the 2 being the conclusion and 1 + 1 being its premises.
Informal Logic – Informal logic looks at the
content of the statement to deduce if it is true, this could
use definitions of a language such as English.
Note: Definition
can change depending on how the word is used and what time
frame and place the definition is being used for, in other
words definitions can have multiple meanings, so be careful.
Arguments - is a series of statement
that can have multiple premises and only one
conclusion.It is
always trying to persuade someone of something. The conclusion
can be stated multiple times, but it is still the same
conclusion.
Discourse - is a connected series of
statements.Arguments
are discourses, but not all discourse is arguments.
Indicator words - help indicate if a argument
is present. However, they don’t always point to an argument
since other sentences like explanations can use them.
Below is a short
list of premise indicator rules:
Furthermore
Because
For
Since
Below is a short
list of conclusion indicator rules:
Therefore
As a result
Hence
Should have
Logically Strong Argument – is any argument where the
premises give good reasons to believe the conclusion.The premises should
be relevant to the conclusion and it should be easy to
understand.The
content should also be probable enough that it can be true.
Valid Argument – is a logically strong
argument where if the premises are true than the conclusion
must be true.
Sound Argument – is a valid argument where
the premises are indeed true and therefore the conclusion must
be true.
Five Different Types of
Statement Forms
Simple form – the
cat is on the mat.
Conjunction – The
cat is on the mat and asleep.
Disjunction – The
cat is either on the mat or on the floor.
Conditional – If
the cat is on the matt then let sleeping cats lie.
Necessary truth – is a statement that is not
a contradiction, and that the statement is always true.For example: At some
point, living creatures will die. You can determine if it is a
necessary truth through its structure, which is called
tautology, or though the content and its intended meaning,
called analytic.
Consistency – an argument is consistent
if the statements have the possibilities to be true at the
same time, otherwise it would be inconsistent.
Dictionary – is a document outlaying the
way that people use words, it is important to note that the a
word can have different meaning depending on how the word is
used in a sentence, the time period the word is being used in,
and the region.
There are
different ways to prove an argument.Three ways to prove
one are:
Deductive Arguments
-Sentence
Structure
Inductive Arguments
-Sampling (ex:
Surveys)
-Generalization
-Analogy
-Mill’s Method
Indirect
-Reduction ad
absurdum(Will be explained later)
Sept 28 / Alex Issa [ to come?]
Oct 1 / Natalie Lesco
Proofs/ Deductive and
Inductive Reasoning
Went over examples from p.27 (Deductive #6,8 - Inductive #9)
-Opinions can be proven
Deductive Arguments
-deduction is a type of validity
Modus ponens (affirming the antecedent)
IF= antecedent THEN= consequent
If A then
B
A
Therefore, B
in other words...
One premise hypothetical/conditional
2nd premise confirm antecedent
Therefore, necessarily the consequent
-validity is not about the truth of the statement, but how the
premises prove the conclusion (it is about the truth of the
structure)
Modus tollens (denying the consequent)
If A then B
Not-B
Therefore, not-A
Conditional chain
If A then B
If B then C
Therefore, if A then C
-if the premise is true, the conclusion must follow
-logic won’t tell you if premises are true
Necessarily follows-> deductive
Probably follows-> inductive
Inductive Arguments
Hint: when an assumption has to be made (ex. assuming that the
past will decide the future)- most likely an inductive
argument
Generalization/Sampling ... always question/evaluate
sources-what is the size of the sample?-what is the spread?-is
the sample random?
Oct 3 / Morag MacDonald
Generalization
In an inductive argument, which depends
on enumeration, we draw a conclusion about all the members
of a class from premises, which refer to some observed
members of that class. Sometimes called sampling.
Ex: All apples in the sample are Grade
A. Therefore, all apples in the barrel are Grade A.
-When the spread is bigger, your
conclusion is more likely to be stronger.
-When the spread is narrowed, for
example, by a certain day of the week (Friday) or certain
group of people (Catholics), it makes the spread smaller
and the conclusion is weaker because of the randomness.
Ex: The six Fromagians were all
Catholics and we saw them on Friday.
-When you take a small sample out of a
large area, then your conclusion is weaker.
Ex: Instead, we concluded that most
Frenchmen ate cheese with white wine.
The word, most, makes your conclusion
mildly weaker because it is a vague word.
Analogy
In an inductive argument that uses
analogy, we draw a conclusion about some thing, based on
relevant similarities that that thing has to another.
Ex. Rats and humans are similar on the
basis of their phycology.
Analogy is based on similarities.
Ask yourself:
Are their similarities relevant?
Are their any dissimilarity’s?
Does it persuade you?
Example: Explorers vs. Students
-Explorers don’t have to take tests.
-Students working conditions are less
dangerous.
-Explorers are adventurous.
-Explorers have more experience,
survival skills and tend to travel in groups with a
leader.
-Explorers are typically older people.
The more relevant similarities, the
stronger the argument and conclusion will be.
The more dissimilarities, the weaker
the argument and conclusion will be.
Oct 5 /
Oct 8 / Stephen MacFarlane
Oct 10 / Ian MacFarlane
Apology occurs in Athens, Ancient Greece
Trojan War - Story of how Prince Paris was promised by the
Gods the most beautiful woman in the world, Helen of Troy. - King Agamemnon was the husband of Helen
of Troy and king of the Troy - Occurred around 1240 BCE Record of the Trojan War was recorded by Homer
in his Iliad in 800 BCE and covered a wide range of topics - Love - Anger and Wrath - Honour and Cowardice - Morality - The Gods and how they interacted with and
actively manipulated humans
Why? (Would the Gods do this?) - Issue of free will. Did Prince Paris have
free will when he took Helen of Troy, or was he being
manipulated? Morality vs Gods - Philosophy starts as a means of discovering
'truths', explanations for why.
Pre-Socratic Philosophy (600 BCE) - People are no longer simply accepting
traditions. Now people are seeking reasons and answers to
understand the nature of reality and wisdom - Pythagoras - Mathematics and Mathematical
Philosophy. Used math to study and understand the nature of
reality - Hippocrates - The Father of Modern
Medicine. The source of the Hippocratic Oath, central to
modern medicine - Muses - Origin of the word 'music',
inspiration for arts and source of knowledge - PhD - Origin of the title 'Doctor' Sophists - 'wise guys' - Knowledge vs thinking you know, largely
focussed upon image - Acted as teachers and advisors, instructing
others as to how to argue - Opinions of Sophists varied greatly. Sophists
were either very appreciated or loathed (popular or
unpopular), depending upon the person asked - Questions of logic, ethics and about 'us'
Is Socrates a Sophist? - Who is Socrates? - What are the charges against Socrates (in the
Apology)? - What special insight or wisdom does Socrates
claim to have?
Oct 12 / Ceilidh Marshall
-Last class we talked about how Greece wasn't as small as it
is today, it was made up of surrounding places as well.
-Reading a text: What is the purpose? Different purposes for different
texts/audiences ie text books are to share common or basic
information while a novel or creative work is usually to share
authors sentiments, get others engaged etc. For public
consumption A philosophical text isn't just a story. Need
to ask why Plato wrote this text. To relay historical info?
Something more? Plato loves/respects Socrates so he's
favourable to him Understanding the context is part of knowing
the purpose -Roots of greek philosophy: Poetic/mythic texts
-Iliad 800 BC Following what the Gods say Beginning around 600 there was an effort to
find naturalistic causes ie why? why is it made of? One of the earliest: cosmological. Became
questions of science Want to find out why Rational/analytical explanations
-Socrates Who was he?: 70 yr old philosopher Likes to talk ie questions/problems Married, has kids Served time as a solider "Teacher", but doesn't call himself one.
Doesn't charge fees Charged with not believing in the Gods and
corrupting the youth He challenges authority Accused of being a sophist
-Sophists: Take weak arguments and make them stronger Make things that aren't true sound plausible Misrepresent reality
Socrates accusers at the trial aren't the only
ones, there are some that go way back who told stories
to the present population when they were younger. Educated
from an early age that Socrates was a problem
The first part of the apology is where Socrates
identifies the accusations and lists a series of explanations
instead of arguments
The oracle says no one is wiser than Socrates.
He denies that and tries to find someone who is in fact wiser,
so he can show that the oracle is wrong. He talks to the
"wisest" people, the ones recognized as experts. Socrates
questions poets (religious texts, traditions, culture),
lawyers/politicians (justice) etc. When he asks them
questions, instead of getting answers, he embarrasses them.
Their reputation seems to make them wise, but he finds out
they actually don't really know what they're talking about. In
this way, he shows that the so called experts know nothing and
annoys the public by undermining authority.
Oct 15 /
Nov.5th, 2012 . Nicole Webb
Justice is…(class answers)
1) Abiding by the rule of the law and following
it in the punishment of criminals.
2) Fair punishment.
3) Fairness and equality
4) No biases, individuals have the right to
defend their positions even if they are harmful to others.
5) What is the morally correct/right thing to
do.
6) The pursuit of fairness, both in and outside
of the formal legal system.
7) A penalty that is fair.
8) What happens after a trial, when peace has
been set and what a person gets what they deserve.
9) Obeying a law or principle.
10) Treating alike cases alike.
11) When a person gets what they deserve.
Different Patterns…
a) Everybody gets an equal share. E.g.
elementary/secondary education.
b) Each according to his or her need. E.g.
welfare
c) Each according to his or her effort.
E.g. grades.
d) Each according to personal merit (virtue)
E.g. promotions.
e) Each according to his or her right.
E.g. inheritance.
f) Each according to whether society wants it
(market) E.g. wealthy professions (doctors)
The Republic “need to knows”
What is it about?
What are the characters?
What are their beliefs?
What is justice? Why does it matter?
What are we suppose to take from the story?
Why is it important? Why should we believe it?
Questions in the Republica.
Why should I be just?
-Consequences now or in the future.
-Physical harm.
-Harm or reputation.
Does Socrates give us a reasonable answer to any of these
questions?
Nov. 7 - Chinakwu Odenigbo
First definition of Justice (Cephalos):
• Speaking the truth and paying whatever debts
one has incurred.
This raises the question: “what is a good definition?”
• A good definition has to be distinctive and
essential
Polemarchos defines justice as:
• To give what is owed to each; i.e “gives
benefits and harms enemies”
Socrates replies this by giving a whole series of analogies with
medicine, warfare, agriculture………
Definition of a table: http://www.thefreedictionary.com/table