Rhetoric
Origins & Devices
Rhetoric

Aristotle (384-322 BC) student of Plato
is considered the father of the modern
study of rhetoric

The art of speaking or writing effectively

The study of writing or speaking as a
means of communication or persuasion
The rhetorical triangle/pyramid
Logos

Logos – appeal to
logic

Pathos – appeal to
emotions

Ethos – appeal to
ethics
Pathos
Ethos
Reasoning

Inductive reasoning
– From specific to general
– Circumstantial / doubt

Deductive reasoning
– From general to specific
– Factual/certainty
Deductive reasoning




Deductive arguments are supposed to be water-tight.
Good deductive argument – both premises are true
and conclusion must be true – there is certainty
The classic example of a deductively valid argument
is:
(1) All men are mortal.
(2) Socrates is a man.
Therefore:
(3) Socrates is mortal.
Inductive Reasoning

Inductive arguments needn’t be as rigorous as
deductive arguments in order to be good arguments.

Good inductive argument – if premises are true,
conclusion may or may not be true, but it is likely –
there is doubt
Logical Fallacies

A logical fallacy is, roughly speaking, an error of
reasoning. When someone adopts a position, or tries
to persuade someone else to adopt a position, based
on a bad piece of reasoning, they commit a fallacy.
Ad hominem /Personal Attack
…a general category of fallacies in which a claim or argument is
rejected on the basis of some irrelevant fact about the author of
or the person presenting the claim or argument.
1. Person A makes claim X.
2. Person B makes an attack on person A.
3. Therefore A's claim is false.
Ex. Su “Doctor Samuels says that the the vitamins are good for
you.”
James “Doctor Samuels was arrested for speeding.
He doesn’t know what is good for you.”
 Ex. "That claim cannot be true. Dave believes it, and we know
how morally repulsive he is.”
 "Bill claims that Jane would be a good treasurer. However I find
Bill's behavior offensive, so I'm not going to vote for Jill."

The Crucible and Ad
Hominem/Personal Attack

Mary Warren claims that all of the behaviors of Abigail and the
rest of the girls are a pretense; they are fake. She indicates that
she too was a part of the hoax. Abigail and the others claim that
she is attacking them by sending out her spirit to claw and
torture them. The courts do not believe Marry Warren’s
testimony.

Mary Warren accuses Goody Good of being a shiftless vagrant
who has practiced witchcraft on her.
Tu quoque

The tu quoque fallacy is committed when a person’s
claim is considered false because it is inconsistent
with that persons words or actions.

"He cannot accuse me of libel because he was just
successfully sued for libel.”
Person 1: It should be illegal to make clothing out of
animals.
Person 2: But, you are wearing a leather jacket.


The Crucible and Tu Quoque

John Proctor claims that Abigail and the girls are faking their
claims, that they are not the voice of God. Cheever points out
that John Proctor does not always go to church and plows on
Sunday. This casts doubt on Proctor’s judgment of the girls’
actions/words.
Ad baculum or Appeal to fear
1.
2.

Y is presented (a claim that is intended to produce fear).
Therefore claim X is true (a claim that is generally, but need
not be, related to Y in some manner).
This line of "reasoning" is fallacious because creating fear in
people does not constitute evidence for a claim.
Ex: ”You know Sarah. I need to pass class, and you need to
maintain your good reputation. If you give me the answers to
the test, I won’t tell others that you stole money from the class
fundraiser.” “But, that’s not true.” “ Who do you think they will
believe?”
The Crucible and Appeal to Fear

Mary Warren warns Elizabeth and John to be careful of their
actions and words toward her. She indicates that she has a
personal connection with the courts and the officers of the
courts. She also points out that she saved Elizabeth’s life by
standing up for her.
Post hoc (ergo propter hoc)
1.
2.
A occurs before B.
Therefore A is the cause of B.

The Post Hoc fallacy derives its name from the Latin phrase
"Post hoc, ergo propter hoc." This has been traditionally
interpreted as "After this, therefore because of this.”

Ex: Sam fell on the stairs before class. His bruised knee is
from the fall.
The Crucible and Post Hoc

The villagers of Andover suffered the symptoms of witchcraft.
The the villagers of Salem begin to suffer strange symptoms.
They must be affected by witchcraft.

Elizabeth Proctor had a doll in court, therefore the pin stuck in
Abigail’s stomach must be from Elizabeth’s poppet.
Slippery slope

The Slippery Slope is a fallacy in which a person asserts that
some event must inevitably follow from another without any
argument for the inevitability of the event in question.

Event X has occurred (or will or might occur).
Therefore event Y will inevitably happen.
This sort of "reasoning" is fallacious because there is no
reason to believe that one event must inevitably follow from
another without an argument for such a claim.
1.

1.
"You can never give anyone a break. If you do, they'll walk all
over you."
The Crucible and Slippery Slope

One person has been accused of witchcraft, therefore all of his
or her acquaintances are likely to also be witches.
False dilemma

1.
2.
3.

1.
2.
3.
A False Dilemma is a fallacy in which a person uses
the following pattern of "reasoning":
Either claim X is true or claim Y is true (when X and Y
could both be false).
Claim Y is false.
Therefore claim X is true.
This line of "reasoning" is fallacious because if both
claims could be false, then it cannot be inferred that
one is true because the other is false. That this is the
case is made clear by the following example:
Either 1+1=4 or 1+1=12.
It is not the case that 1+1=4.
Therefore 1+1=12.
The Crucible and False Dilemma



Either the girls danced, chanted and drank blood and are
witches or they are not witches.
The girls drank, chanted, and drank blood.
They must be witches.
False authority

1.
2.
3.

1.
An Appeal to Authority is a fallacy with the following form:
Person A is (claimed to be) an authority on subject S.
Person A makes claim C about subject S.
Therefore, C is true.
This fallacy is committed when the person in question is not a
legitimate authority on the subject. More formally, if person A
is not qualified to make reliable claims in subject S, then the
argument will be fallacious.
Dave and Kintaro are arguing about Stalin's reign in the
Soviet Union. “Stalin was a great leader while Kintaro
disagrees with him. Kintaro: "I don't see how you can consider
Stalin to be a great leader. He killed millions of his own
people, he crippled the Soviet economy, kept most of the
people in fear and laid the foundations for the violence that is
occurring in much of Eastern Europe."
Dave: "Yeah, well you say that. However, I have a book at
home that says that Stalin was acting in the best interest of
the people. The millions that were killed were vicious enemies
of the state and they had to be killed to protect the rest of the
peaceful citizens. This book lays it all out, so it has to be true."
The Crucible and False Authority


Hale is supposed to be an authority on witches and witchcraft.
Hale signs papers indicating that women are witches.
Therefore, the women are indeed witches.
Source Cited
Labossiere, Michael C. The Nizkor Project, 1991-2009. 9 Jul. 2009.
< http://www.nizkor.org/features/fallacies/>.