Informal Fallacies
Domenic Marbaniang. 2019
Formal Vs Informal fallacies
Formal fallacies occur due to errors in the form or structure of the argument. For instance, the following
form of argument is invalid; therefore, it commits a formal fallacy:
If p then q
q
Therefore, p
The valid form would be
If p then q
Not q
Therefore, not p
Informal fallacies occur due to errors in the content of the argument. For instance,
Ears are organs of hearing.
Corns have ears
Therefore, corn ears are organs of hearing.
In the above argument, the term “ears” has different meanings in premises which is mixed up in the
conclusion leading to the informal fallacy of equivocation.
Informal Fallacies
When the form seems valid, yet the conclusion is false
Problem of Induction? How do you interpret data?
Some popular fields where informal fallacies are found
1. Sales and Marketing
2. Political campaigning
3. TV Journalism
4. Polls and Surveys
5. Criminal investigation
6. Court arguments
7. Empirical and Inductive research
How identifying fallacies helps
1. Helps to evaluate logical proofs/arguments
2. Helps to construct fallacy-proof arguments
3. Helps to conduct reliable research
Informal fallacies
May have psychological appeal
But they lack philosophical justification.
Some of the many Informal Fallacies
1. False Cause
2. Bandwagon
3. Begging the Question
4. Strawman
5. Ad Hominem
6. Appeal to Unqualified
Authority
7. Question fallacies
8. Equivocation
9. False Dilemma
10. Chronological Snobbery
11. Hasty Generalization
12. Appeal to emotion
1. False Cause
Sequential things may be causally related His hair turned grey after his
daughter’s marriage. It’s because of
her marriage.
In reality, his grey hair has nothing to do with
his daughter’s marriage.
False Cause
Everytime a black cat crosses the
path, I have a bad day
In reality, no evidence is available to
establish the relation between the black cat
and a bad day
False Cause & Conditioning
Classical Conditioning: Dog, Bell, and Food
Operant Conditioning: Rat,
Lever, and Food
2. Bandwagon (Appeal to Majority)
That which is most popular might be most reliable
2. Bandwagon (Appeal to Majority)
That which is most popular might be most reliable
Some Examples:
1. Most people use iPhones, so
iPhones should be the best
phones
2. Most people believe in
astrology, so astrology must be
true
3. The video with most likes is the
best one.
3. Begging the Question (Petitio Principii)
Assuming the very thing that needs to be proved
B
As per strata classification, the
strata at which the fossil is
found is 3 million years old
A
Fossil evidence indicates this
strata is 3 million year old
Circular Argument
How do you know that?
Begged Question
Begging the Question (Petitio Principii)
Assuming the very thing that needs to be proved
B
The Bible is the word of God
A
The Bible is true
Circular Argument
How do you know that?
Begged Question
Begging the Question (Petitio Principii)
Assuming the very thing that needs to be proved
B
There is no proof for the
existence of God
A
God does not exist
Circular Argument
How do you know that?
Begged Question
Begging the Question (Petitio Principii)
Assuming the very thing that needs to be proved
B
Factual impossibility of
performing conspiracy cannot be
brought against the charge of
conspiracy
A
Federal jurisdiction exists
Circular Argument
How do you know that?
Begged Question
4. Straw man fallacy
1. Socrates says that the young people
should have freedom of thought.
2. What Socrates means is that the young
people should rebel against the gods of
our tradition.
3. Such rebellion is lethal to social harmony.
4. Therefore, Socrates is anti-social.
The argument distorts
Socrates’ view of the freedom
of thought to mean rebellion
against popular religion. This
is a strawman.
Creating a false, exaggerated, or distorted easily
defeatable caricature and attacking it instead of
addressing the real issue.
Any resemblance in Social psychology and Psychology of spiritualism?
Ef i y n s, Vil hi n
5. Ad Hominem
(Argument against the person)
Attacking the person rather than
addressing the argument
1. You are trying to prove that smoking is injurious to health,
but you jumped the red traffic signal the other day, you are
not law abiding. Therefore, your arguments are nonsensical.
2. I cannot accept the teachings of Christianity because the
Colonialists were Christians and they plundered the world.
3. Mr. Rudolf has argued that the shifting of our business
centre to Coven Road should be highly advantageous.
However, we all know that Mr. Rudolf resides at Coven
Road and it is possible that he wishes to shift the business
for his own personal advantage. Therefore, his arguments
should be dismissed.
5. Ad Hominem and Psychology
(Disposition against/towards the person)
❏ I want to believe what you believe because
I like you so much!
❏ I don’t like his ideas because I don’t like
him; so, his ideas are trash.
❏ If you don’t respect my ideas, I have no
respect for yours either.
6. Appeal to Unqualified Authority
Arguing from reliance on an unreliable authority
1. The Beatles were the most popular rock band in the 70s and they
turned to Transcendental Meditation, proving that Transcendental
Meditation is the true way.
2. The famous American actress and author Shirley MacLaine is also a
strong believer in New Age philosophy proving that New Age philosophy
is the key to ultimate truth and meaning in life.
3. Joachim Ernst Berendt was a great musician and believed that music is
the key to spirituality. Therefore, music is the key to spirituality.
7. Question Fallacies
Questions leading to or loaded with or forcing intended answers
1. On April 9, did you see the defendant shoot the
deceased? (leading question)
What did you see on April 9? (straight)
2. Where did you hide the cookies that you stole?
(loaded question)
Did you steal the cookies? If you did where did
you hide them? (straight)
3. How can you say that you can’t come? (coercive
question)
Will you come? (straight)
8. Equivocation
Misleading an argument by mixing up word-meanings
9. False Dilemma/Dichotomy
1. Either you are a theist or an atheist.
2. You are not a theist.
3. Therefore, you are an atheist.
But, there could be another possibility: you
are an agnostic
1. Either you like chocolate or you like cake.
2. You don’t like cake.
3. Therefore, you like chocolate.
But you may not like either.
10. Chronological Snobbery
1. Hinduism is the oldest living religion; therefore,
Hinduism is the truest religion.
2. Modern science does not have any use for the God
hypothesis; therefore, theism is redundant.
3. Sexual chastity is a tenet of superstitious archaic
societies; modern societies are sexually liberal.
Therefore, sexual libertarianism is true.
4. Since history past women have been subordinate to
men; therefore, women must be subordinate to men.
Argument from superiority owing to time-factor
● The older is the more reliable
● The newer is the more reliable
11. Hasty Generalization
Drawing general conclusions without sufficient research
1. I was cheated by a Greek guy;
therefore, all Greeks are cheats.
2. Plato’s Parmenides is a very difficult
read. Therefore, Plato’s writings are
difficult to understand.
3. Shakespeare’s Romeo and Juliet is a
romantic tale. Therefore, Shakespeare
mainly wrote romantic plays.
12. Appeal to Emotion
Attempt to manipulate emotions
12. Appeal to Emotion
Attempt to manipulate emotions
Four - four mouthfuls.
- Nope, I'm not - That's two times two.
Come on, four.
No, I'm just eating two things.
- Three? - One and a half.
There are children in Africa who are starving.
They'd love to eat all this stuff.
(Sighs) Why don't you just send it to them? Go buy an envelope and send
it to them.
You can't put this in an envelope, can you? It'd all get crushed.
You'd get sort of soup.
Well, you could put each thing in a plastic bag and put it in the thing, and
then send it.
(Outnumbered, BBC)

Some informal fallacies

  • 1.
  • 2.
    Formal Vs Informalfallacies Formal fallacies occur due to errors in the form or structure of the argument. For instance, the following form of argument is invalid; therefore, it commits a formal fallacy: If p then q q Therefore, p The valid form would be If p then q Not q Therefore, not p Informal fallacies occur due to errors in the content of the argument. For instance, Ears are organs of hearing. Corns have ears Therefore, corn ears are organs of hearing. In the above argument, the term “ears” has different meanings in premises which is mixed up in the conclusion leading to the informal fallacy of equivocation.
  • 3.
    Informal Fallacies When theform seems valid, yet the conclusion is false
  • 4.
    Problem of Induction?How do you interpret data?
  • 5.
    Some popular fieldswhere informal fallacies are found 1. Sales and Marketing 2. Political campaigning 3. TV Journalism 4. Polls and Surveys 5. Criminal investigation 6. Court arguments 7. Empirical and Inductive research
  • 6.
    How identifying fallacieshelps 1. Helps to evaluate logical proofs/arguments 2. Helps to construct fallacy-proof arguments 3. Helps to conduct reliable research
  • 7.
    Informal fallacies May havepsychological appeal But they lack philosophical justification.
  • 8.
    Some of themany Informal Fallacies 1. False Cause 2. Bandwagon 3. Begging the Question 4. Strawman 5. Ad Hominem 6. Appeal to Unqualified Authority 7. Question fallacies 8. Equivocation 9. False Dilemma 10. Chronological Snobbery 11. Hasty Generalization 12. Appeal to emotion
  • 9.
    1. False Cause Sequentialthings may be causally related His hair turned grey after his daughter’s marriage. It’s because of her marriage. In reality, his grey hair has nothing to do with his daughter’s marriage.
  • 10.
    False Cause Everytime ablack cat crosses the path, I have a bad day In reality, no evidence is available to establish the relation between the black cat and a bad day
  • 11.
    False Cause &Conditioning Classical Conditioning: Dog, Bell, and Food Operant Conditioning: Rat, Lever, and Food
  • 12.
    2. Bandwagon (Appealto Majority) That which is most popular might be most reliable
  • 13.
    2. Bandwagon (Appealto Majority) That which is most popular might be most reliable Some Examples: 1. Most people use iPhones, so iPhones should be the best phones 2. Most people believe in astrology, so astrology must be true 3. The video with most likes is the best one.
  • 16.
    3. Begging theQuestion (Petitio Principii) Assuming the very thing that needs to be proved B As per strata classification, the strata at which the fossil is found is 3 million years old A Fossil evidence indicates this strata is 3 million year old Circular Argument How do you know that? Begged Question
  • 17.
    Begging the Question(Petitio Principii) Assuming the very thing that needs to be proved B The Bible is the word of God A The Bible is true Circular Argument How do you know that? Begged Question
  • 18.
    Begging the Question(Petitio Principii) Assuming the very thing that needs to be proved B There is no proof for the existence of God A God does not exist Circular Argument How do you know that? Begged Question
  • 19.
    Begging the Question(Petitio Principii) Assuming the very thing that needs to be proved B Factual impossibility of performing conspiracy cannot be brought against the charge of conspiracy A Federal jurisdiction exists Circular Argument How do you know that? Begged Question
  • 20.
    4. Straw manfallacy 1. Socrates says that the young people should have freedom of thought. 2. What Socrates means is that the young people should rebel against the gods of our tradition. 3. Such rebellion is lethal to social harmony. 4. Therefore, Socrates is anti-social. The argument distorts Socrates’ view of the freedom of thought to mean rebellion against popular religion. This is a strawman. Creating a false, exaggerated, or distorted easily defeatable caricature and attacking it instead of addressing the real issue.
  • 21.
    Any resemblance inSocial psychology and Psychology of spiritualism? Ef i y n s, Vil hi n
  • 22.
    5. Ad Hominem (Argumentagainst the person) Attacking the person rather than addressing the argument 1. You are trying to prove that smoking is injurious to health, but you jumped the red traffic signal the other day, you are not law abiding. Therefore, your arguments are nonsensical. 2. I cannot accept the teachings of Christianity because the Colonialists were Christians and they plundered the world. 3. Mr. Rudolf has argued that the shifting of our business centre to Coven Road should be highly advantageous. However, we all know that Mr. Rudolf resides at Coven Road and it is possible that he wishes to shift the business for his own personal advantage. Therefore, his arguments should be dismissed.
  • 23.
    5. Ad Hominemand Psychology (Disposition against/towards the person) ❏ I want to believe what you believe because I like you so much! ❏ I don’t like his ideas because I don’t like him; so, his ideas are trash. ❏ If you don’t respect my ideas, I have no respect for yours either.
  • 24.
    6. Appeal toUnqualified Authority Arguing from reliance on an unreliable authority 1. The Beatles were the most popular rock band in the 70s and they turned to Transcendental Meditation, proving that Transcendental Meditation is the true way. 2. The famous American actress and author Shirley MacLaine is also a strong believer in New Age philosophy proving that New Age philosophy is the key to ultimate truth and meaning in life. 3. Joachim Ernst Berendt was a great musician and believed that music is the key to spirituality. Therefore, music is the key to spirituality.
  • 25.
    7. Question Fallacies Questionsleading to or loaded with or forcing intended answers 1. On April 9, did you see the defendant shoot the deceased? (leading question) What did you see on April 9? (straight) 2. Where did you hide the cookies that you stole? (loaded question) Did you steal the cookies? If you did where did you hide them? (straight) 3. How can you say that you can’t come? (coercive question) Will you come? (straight)
  • 26.
    8. Equivocation Misleading anargument by mixing up word-meanings
  • 27.
    9. False Dilemma/Dichotomy 1.Either you are a theist or an atheist. 2. You are not a theist. 3. Therefore, you are an atheist. But, there could be another possibility: you are an agnostic 1. Either you like chocolate or you like cake. 2. You don’t like cake. 3. Therefore, you like chocolate. But you may not like either.
  • 29.
    10. Chronological Snobbery 1.Hinduism is the oldest living religion; therefore, Hinduism is the truest religion. 2. Modern science does not have any use for the God hypothesis; therefore, theism is redundant. 3. Sexual chastity is a tenet of superstitious archaic societies; modern societies are sexually liberal. Therefore, sexual libertarianism is true. 4. Since history past women have been subordinate to men; therefore, women must be subordinate to men. Argument from superiority owing to time-factor ● The older is the more reliable ● The newer is the more reliable
  • 30.
    11. Hasty Generalization Drawinggeneral conclusions without sufficient research 1. I was cheated by a Greek guy; therefore, all Greeks are cheats. 2. Plato’s Parmenides is a very difficult read. Therefore, Plato’s writings are difficult to understand. 3. Shakespeare’s Romeo and Juliet is a romantic tale. Therefore, Shakespeare mainly wrote romantic plays.
  • 31.
    12. Appeal toEmotion Attempt to manipulate emotions
  • 33.
    12. Appeal toEmotion Attempt to manipulate emotions Four - four mouthfuls. - Nope, I'm not - That's two times two. Come on, four. No, I'm just eating two things. - Three? - One and a half. There are children in Africa who are starving. They'd love to eat all this stuff. (Sighs) Why don't you just send it to them? Go buy an envelope and send it to them. You can't put this in an envelope, can you? It'd all get crushed. You'd get sort of soup. Well, you could put each thing in a plastic bag and put it in the thing, and then send it. (Outnumbered, BBC)