This 3-sentence summary provides the high-level information about the document: The document outlines a midterm review for a logic course, including that there will be 35 multiple choice, true/false questions worth a total of 100 points. Students have one attempt to complete the exam with no time limit by the due date of October 19th at 11:59 PM with no late submissions or exceptions allowed. The document also provides tips for students to prepare and review key concepts that will be covered on the exam such as recognizing arguments, deductive vs inductive arguments, validity and soundness, and common fallacies.

1. Midterm Review
Logic 105
Rosibel O’Brien-Cruz

2. Logistics
35 Questions
• M
ultiple Choice
• T/F
• 100 Points Total
Due: October 19
• 11:59 PM
• No Late Submissions
• No exceptions
Attem
pts
• One Attem
pt Only
• Save Responses
• No Tim
e Lim
it

3. Tips
Prepare
Print Notes
Pencil/Paper
Organize
Notes
Reliable
Internet
Allot time

4. Statements and Arguments
Argument
• A group of statements in which
the conclusion is claimed to
follow from the premise(s)
Statement
• A sentence that is either true
or false
Truth value
• Every statement has a truth
value (either true or false)

5. Recognizing Arguments
Arguments
contain
premise(s) in
support of a
conclusion
We should boycott that
company. They have been
found guilty of producing
widgets that they knew were
faulty, and that caused
numerous injuries.
Conclusion and
premise
indicators help
us identify
arguments
Since they have been found
guilty of producing widgets
that they knew were faulty,
and that caused numerous
injuries, we should therefore
boycott that company.

6. Recognizing Arguments
Identify the premises and conclusion
Buy an Apple
instead of a
Windows
computer, because
Apple computers
have more features
for graphic artists
and you are a
graphic artist.
Answer
Premise (a) Apple
computers have more
features for graphic artists.
Premise (b) You are a
graphic artist.
Conclusion: Buy an Apple
instead of a Windows
computer.

7. Deductive and Inductive Arguments
Deductive
argument
Inductive
argument
• One in which it is claimed that
• The conclusion follows
necessarily from the premises
• True premises make it
impossible for the conclusion to
be false
• One in which it is claimed that
• The premises make the
conclusion probable
• True premises make it
improbable for the conclusion to
be false

8. Identifying Deductive and
Inductive Arguments
Key words/phrases
Deductive:
necessarily, certainty,
definitely
Inductive:
probably, likely,
unlikely, plausible
Strength of argument
Deductive:
conclusion necessarily
true
Inductive:
conclusion only
probably true
Types of arguments
Deductive:
mathematics,
geometry, definitions
Inductive:
analogical, legal,
moral, statistical,
scientific (see Part IV)

9. Inductive Arguments: Strength and Cogency

10. Incomplete Arguments
Enthymemes: Arguments with missing premises, missing
conclusions, or both.
• I have a Cadillac; therefore I don’t have to spend much on maintenance.
• I have a Cadillac. [Cadillacs require very little maintenance]; therefore, I don’t have to spend much on
maintenance.
Principle of charity: We should choose the reconstructed argument that
gives the benefit of the doubt to the person presenting the argument.

11. What’s Missing? It’s a Woody Allen
film. I don’t like
Woody Allen films.
Answer
Missing
conclusion.
It’s a Woody Allen
film.
I don’t like Woody
Allen films.
[Therefore, I know
I won’t like it.]

12. Deductive or Inductive?
• Most college freshman have
part-time jobs. Sue is a
college freshman. Thus, Sue
has a part-time job.
Deductive or
Inductive?
• If the premises are true, then
it is probably true that Sue
has a part-time job.
However, the conclusion can
be false, since we are told
only that "most" college
freshmen have part-time
jobs.
Inductive • All college freshmen have
part-time jobs. Sue is a
college freshman. Thus, Sue
has a part-time job. (If the
premises are true, then it
follows necessarily that Sue
has a part-time job.)
Compare
(Deductive)

13. Logical Analysis tells whether a deductive argument is
valid or invalid.
True premises
make it impossible
for the conclusion
to be false
Valid Even if the
premises are true,
it is still possible
for the conclusion
to be false
Invali
d

14. Truth Analysis tells whether a deductive argument is
sound or unsound.
The argument
is valid and the
premises are, in
fact, true
Sound
The argument
is invalid or at
least one
premise is false
Unsound

15. Deductive Arguments: Validity and Soundness
•Logical Form
• Helps to separate logical from truth analysis
All beagles are dogs
All dogs are mammals.
All beagles are mammals.
Form All B are D.
All D are M.
All B are M.
Any substitutions in
this exact form will
also be VALID
VALID ARGUMENT

16. Deductive Arguments: Validity
and Soundness
•Counterexample to a statement
– Provides evidence that a statement is false
•Counterexample to an argument
– Shows that true premises do not make the conclusion necessarily true
(argument is invalid)
All B are S. Substitutions All men are human beings. (T)
All G are S. All women are human beings. (T)
All B are G. All men are women. (F)

17. Deductive Arguments: Validity and Soundness

18. Use Counterexample to show validity or
invalidity
Argument
No C are B.
No C are S.
No B are S.
Answer
(it’s possible to find
true premises together
with a false conclusion
using this logical form):
Invalid.
Counterexample
No crocodiles are boas.
(T)
No crocodiles are
snakes. (T)
No boas are snakes. (F)

19. Using Extensional Definitions
• Assigns meaning to a term by indicating the class members denoted by the term.
An extensional
(denotative) definition
• Involves demonstrating the term—
• Example: pointing, gesturing, drawing a picture, or showing a photographOstensive definitions
• Assigns meaning to a term by naming the individual members of the class denoted by the term
• Example: New England" means Connecticut, Maine, Massachusetts, New Hampshire, Rhode
Island, and Vermont.
Enumerative
definitions
• Assigns meaning to a term by naming subclasses (species) of the class denoted by the term.
• Example: "Coal" means lignite, subbituminous, bituminous, and anthraciteDefinitions by subclass

20. Intensional DefinitionsAnintensional
(connotative)definition
Assigns a meaning to a term by listing
the properties shared by all the objects
that are denoted by the term.
Strategiesusedtoclarify
intensionaldefinitions
Synonymous Definitions Assigns a
meaning to a term by providing
another term with the same meaning
Word Origin Definitions Assigns a
meaning to a term by investigating its
origin.
Operational Definitions Assigns
meaning to a term by specifying a
measurement procedure.
Definition by Genus and Difference
•Assigns a meaning to a term (the species) by
establishing a genus and combining it with the
attribute that distinguishes the members of
that species.

21. Applying Definitions
Stipulative
Definitions
Introduces a new meaning to a term or symbol
Lexical Definitions A definition based on the common use of a word, term, or symbol
Functional
Definitions
Specifies the purpose or use of the objects denoted by the term
Precising
Definition
Reduces the vagueness and ambiguity of a term by providing a sharp focus, often a
technical meaning, for a term.
Theoretical
Definitions
Assigns a meaning to a term by providing an understanding of how the term fits into a
general theory
Persuasive
Definitions
Assigns a meaning to a term with the direct purpose of influencing attitudes or
opinions

22. What type of definition?
A microwave oven is an oven in
which food is cooked, warmed, or
thawed by the heat produced as
microwaves cause water molecules
in the foodstuff to vibrate.
Answer Functional definition

23. Guidelines for Informative Definitions
An informative
definition should use
quote marks
appropriately.
An informative
definition should
include the essential
meaning of a term.
An informative
definition should not be
too broad or too
narrow.
An informative
definition should not be
circular.
An informative
definition should be
affirmative and not
negative.
An informative
definition should not
use ambiguous or vague
language.
An informative
definition should not
use emotionally
charged or figurative
language.
An informative
definition should
include a context
whenever necessary.

24. Informative
Definitions
A lawyer is a person
who writes a
10,000-word document
and calls it a “brief.”
- Franz Kafka
Violates:
2. An informative
definition should
include the essential
meaning of a term.
8. An informative
definition should
include a context
whenever necessary.

25. Cognitive and Emotive Meaning
Cognitive
meaning:
Language that is used to
convey information has
cognitive meaning.
It's already 7 o'clock. He is late
for the appointment.
Emotive
meaning:
Language that is used to
express emotion or feelings
has emotive meaning.
It's already 7 o'clock. He is late
for the appointment. I am fed
up with his nonsense; he is
completely untrustworthy,
self-centered, and useless.
Contains a value claim: A
judgment that someone (or
something) is good or bad,
moral or immoral, or better or
worse than another person (or
thing). (See Ch. 12)

26. Cognitive and Emotive Meaning: Determine the
type of meaning expressed in the following
Americans gave a total of nearly $347
billion to charity in 2011, a 7.5 percent
increase over 2010, according to a
report released Tuesday by Atlas of
Giving.
The first sentence contains cognitive
meaning.
It’s well known that many charities
are corrupt; the people running these
scams are despicable and immoral
scoundrels who probably keep most of
this money for themselves.
The second sentence includes a value
claim and therefore contains emotive
meaning.

27. Factual Disputes
Factual dispute:
Occurs when people
disagree on a matter that
involves facts.
May involve different
emotional attitudes toward
the fact
Example
Our state legislature should
pass a law authorizing
capital punishment because
it is an effective deterrent
to violent crime.
Our state legislature should
not pass a law authorizing
capital punishment because
it has not been shown to be
an effective deterrent to
violent crime.

28. Factual and Verbal Disputes
Verbal dispute:
Occurs when a vague or
ambiguous term results in
a linguistic
misunderstanding.
Requires investigating the
definitions, not the facts
May involve emotive
meanings, political or
religious divisions, and
value claims, making it
difficult to agree on a
definition

29. Is the following a factual dispute or a verbal
dispute?
Pregnant women should limit their
caffeine intake to 200 mg a day in
order to avoid the risk of miscarriage.
Answer
Factual dispute
• There is no link between caffeine
consumption and miscarriage in
pregnant women.

30. The Basics of
Diagramming
Arguments
•Diagram of a simple argument:
1
"You do not take care of your dog.
2
Therefore, you will not be able to
accept the responsibility of owning a
car."
Diagramming an argument allows
us to visualize the connections
between the premise(s) and the
conclusion.
1
2

31. Convergent Diagram
1
You will not be able to accept the responsibility of
owning a car because 2
you do not take care of your
dog,3
you don’t clean your room, and 4
you do not
handle your money responsibly.Reveals the occurrence of
independent premises
Premises are independent when
the falsity of one does not nullify
any support the others would give
to the conclusion.

32. Linked Diagram
1
The movie version of The Lord of the Rings used
some of the original dialogue from the books, 2
it used
the language Tolkien invented, 3
it used the characters
he created, 4
it kept the overall plot, and 5
the settings
were the same as in the books. Therefore, 6
the movie
trilogy Lord of the Rings captured most of the spirit of
the original books.
Reveals the occurrence of
dependent premises
Premises are dependent
when they act together to
support a conclusion.

33. Divergent Diagram
1
The new movie Son of Avatar will be the highest
grossing movie in history. Therefore, 2
it is sure to win
multiple Academy Awards, and 3
some of the actors
will be among the highest paid in the industry. We can
also conclude that 4
the director will get to do
anything he wants in the near future.
Shows a single premise supporting
independent conclusions.

34. Serial Diagram
1
The government just cut taxes and 2
put a freeze on
the minimum wage. 3
This combination is sure to
create higher unemployment. Of course, 4
that will
lead to a drop in gross domestic sales. 5
This will surely
cause a recession.Shows that a conclusion from one
argument is a premise in a second
argument.

35. Diagramming
Sentences
Since cable news shows are
politically biased and people
appearing on these shows have
extreme ideological views, we can
conclude that cable news shows do
not give us an honest account of
events.
1
Since cable news shows are politically biased and 2
people
appearing on these shows have extreme ideological views, 3
we can conclude that cable news shows do not give us an
honest account of events.

36. Fallacies Based on Personal Attacks or
Emotional Appeals
Fallacies Based on Personal
Attacks
Ad hominem
abusive
Ad hominem
circumstantia
l
Poisoning the
well
Tu quoque
Fallacies Based on Emotional
Appeals
Appeal to
the people
Appeal to
pity
Appeal to
fear or
force

37. Weak Inductive Argument Fallacies
Rigid application of
a generalization
Hasty
generalization
Composition
Division Biased sample
FALSE CAUSE
FALLACIES:
• Post hoc
• Slippery slope

38. Fallacies of Unwarranted Assumption
Begging the
Question
Complex
Question
Appeal to
Ignorance
Appeal to an
unqualified
authority
False
dichotomy
Arguments that assume
the truth of some
unproved or
questionable claim.

39. Fallacies of Diversion
A fallacy that occurs when
the meanings of terms or
phrases are changed
(intentionally or
unintentionally) within the
argument, or when our
attention is purposely (or
accidentally) diverted from
the issue at hand.
Equivocation Straw Man
Red Herring
Misleading
Precision
Missing the
Point

40. Appeal to Fear or
Force
1
If the workers of this company do not
agree to a 25% cut in salary, then the
company may have to shut its doors.
Therefore, 2
the workers of this company
must agree to a 25% cut in salary
A threat of harmful consequences
(physical and otherwise) used to
force acceptance of a course of
action that would otherwise be
unacceptable.
The premise is an obvious threat without providing
objective evidence for the conclusion.

41. Slippery Slope
• 1
If you start smoking marijuana for
pleasure, you will need more and more to
achieve the expected high. 2
You will
begin to rely on it whenever you feel
depressed. 3
Eventually you will
experiment with more powerful drugs. 4
The amount of drug intake will have to
increase to achieve the desired results. 5
At this point, the addiction will take hold
and will lead to a loss of ambition, a loss
of self-esteem, the destruction of your
health, and the dissolution of all social
ties. Therefore, 6
you should not start
smoking marijuana.
Attempts to make a final event the
inevitable outcome of an initial act.
Relies on a causal network with each step in the chain causing
next step. The alleged inevitability of the final act needs is not
supported by objective evidence.

42. Complex
Question
•
• 1
I asked you if you still cheated on your taxes. 2
You said "No." Therefore, 3
by your own admission
you did cheat on your taxes.A single question that actually contains
multiple parts and an unestablished hidden
assumption.
Do you still cheat on your taxes?
Answering “yes” or “no”
presumes you do or did
cheat on your taxes.
The premises rely on two distinct
questions: A. Did you ever cheat on your taxes? B. Do you
now cheat on your taxes?
1 2
3

43. Appeal to
Ignorance
• 1
There is no life anywhere else in the universe.
2
We have never received signals from any
part of space.
An argument built on a
position of ignorance claiming
either:
1. a statement must be true
because it has not been
proven to be false or
2. a statement must be false
because it has not been
proven to be true. The conclusion is based on the lack of signals from outer
space, while our failure to detect signals may signify our
ignorance of better methods for detecting life.
2
1

44. Biased Sample
1
Evidence shows that approximately 85% of all
Americans believe that abortion is morally
wrong. 2
Recently, a sample of Catholics
revealed that 85% believe that abortion is
morally wrong.
Uses a non-representative sample as support
for a statistical claim about an entire
population.
The sample surveyed only Catholics, but the conclusion generalizes
to all Americans.
1
2

45. Trouble?
Helpdesk:
•ccc.ed/help
•(312) 553-2600
Contact me at:
•rcruz27@ccc.edu
•(773) 609-3651