Reasoning

How to Detect and Prevent Sloppy or Manipulative Thinking

Reasoning is either cogent (good) or fallacious

(bad)

Cogent thinking satisfies the following conditions:

1. Premises are believable given what we already know

2. We consider all relevant information 3. Our reasoning is valid (premises provide strong

grounds for accepting the claim/conclusion we draw

Cogent Thinking

Requires we bring to bear relevant

background beliefs + info

Example: Capital punishment argument premise that taking the life of a human is always wrong.

Most ppl not pacifists + don’t believe it’s always wrong to take human life. So = premise is questionable + conclusion should not be accepted.

Believable Premises

We must resist temptation to neglect evidence

contrary to what we want to believe.

Student in college drawn in to stock trading in 90s b/c other students made $

- Student wiped out when tech stocks crashed in 2000-2001.

- His reasoning neglected several points – most important being = stocks go down too

Relevant Information

Premise(s) of argument must genuinely

support conclusion

Two kinds A. Deductive: if all premises are true, then

claim must be true too – syllogistic form1. If A then B2. A.

3.B.

Valid Reasoning

1. If this wire is made of copper, then it will conduct

electricity. (Premise)2. This wire is made of copper. (Premise)3. This wire will conduct electricity. (Conclusion)

The form of the argument makes it valid –

- or invalid

Example

Definition: Learning from

experience

Used so frequently – goes unnoticed.

Benefit comes at cost of increase in possibility of error.

Inductive leaps can lead us astray

Inductive Validity

The tooth fairy

turned out not to be real. The Easter Bunny turned out not to be real. So I’m beginning to wonder about Santa.

So, what can we induce about owls here?

Valid Examples

Last week, I went to Rocco’s Restaurant for the first time and had a terrible meal. I will never go back.

Questionable Induction

Good reasoning is often considered:

1. Culturally relative or gender relative2. Feminine logic vs. male logic3. Black intelligence different from Eurocentric

white intelligence4. “That might be true for you, but it isn’t true for

me.”

Intuitive or wishful reasoning is not reasoning.

People Think Illogically

A large majority of the scientists who laid the

groundwork in physics, chemistry, and biology were white males. - What reason would anyone have to deny what

their experience teaches us?- Would the outcomes be different if there were

more women or minorities involved?- There is no truth WHATSOEVER To the idea that

standards of good reasoning differ from group to group, male to female, person to person.

Example

Self-interest, prejudice, narrow-mindedness do

lead people to think invalidly.

Self-interest often motivates us to neglect values + interests of others.

Testing our beliefs in terms of our experiences + of what we learn from others is to weed out those that are false.

HOWEVER…

1. Culture: Our understanding of the world from our communities

Includes family, ethnicity and associations whoseunderstanding of the world seeps into our thoughts and perceptions from the time we are children to the present.

2. Education:  The systematic learning of the schools, elementary, primary, secondary, university and vocational which infuses our understanding of the world.

For example, a child might be confronted by beliefs outside of the culture and religion at school.  The processing of this

conflict shapes a person’s worldview.

3. Religion: A set of beliefs about the origins of life These can be cultural or can differ from the culture in which a person was raised.

 

Worldview – Everybody Has One

4. Experiences: Personal events in a person’s life impact the

way the world is viewed by each person.

5. Environment: The area in which we live directly impacts our understanding of the world; someone who lives in the desert, will see the world from a different vantage as one who live in the artic.

7. Family: Parents, brothers, sisters, aunts and uncles’ views influence our view in one way or another. 

8. Friends: The power of what our peers think and feel about the world will also shape our perception. 

Worldview cont.

*character, virtue, discipline, tough it out, strong, self-

reliant, individual responsibility, standards, authority, heritage, competition, earn, hard work, enterprise, property rights, reward, traditional, intrusion, meddling, punishment, human nature, common sense, dependency, self-indulgent, elite, quotas, breakdown, corrupt, decay, rot, degenerate, deviant, lifestyle.

What do these words say about the conservative world view?

Words Used by Conservatives Repeatedly in Speeches

*Taken from George Lakoff’s book, Moral Politics: How Liberals and Conservatives Think, (Lakoff is a University of California professor of linguistics.)

*Social forces, social responsibility, free

expression, human rights, equal rights, concern, care, help, health, safety, nutrition, basic human dignity, oppression, diversity, deprivation, alienation, big corporations, corporate welfare, ecology, ecosystem, biodiversity, pollution

What do these words say about the liberal world view?

Words Used Repeatedly by Liberals in Speeches

*Taken from George Lakoff’s book, Moral Politics: How Liberals and Conservatives Think, (Lakoff is a University of California professor of linguistics.)

QUESTIONABLE PREMISE – accepting premises we

should doubt

SUPPRESSED EVIDENCE – neglecting relevant evidence

INVALID INFERENCE – drawing conclusions not supported by evidence

Fallacies: 3 Types

Some authorities

more trustworthy + reliable than others

Become your own expert on controversial topics

Appeal to Authority

“Al Gore – almost president, not a scientist, here to tell you about the dangers of global warming. All scientists agree that it’s real, it’s man-made, and it’s going to kill us all. Trust me.”

No Need to Panic About Global Warming (Signed by 16 Scientists, The Wall Street Journal, January 26, 2012)

Concerned Scientists Reply on Global Warming (Signed by 16 Scientists, The Wall Street Journal, February 21, 2012)

Global Warming Models Are Wrong Again (William Happer, Ph.D. Professor of Physics, Princeton University, The Wall Street Journal, March 27, 2012)

49 former NASA scientists go ballistic over agency's bias over climate change (Financial Post, April 11, 2012)

Articles Revealing Actual Scientists’ Views of GW

Dr. Jan Esper’s Study on Climate Change Published July 2012

Johannes Gutenberg University Mainz , Germany

Johannes Gutenberg University Mainz :

Professor Dr. Jan Esper's group at the Institute of Geography at JGU used tree-ring density measurements from sub-fossil pine trees originating from Finnish Lapland to produce a reconstruction reaching back to 138 BC.

In so doing, the researchers have been able for the first time to precisely demonstrate that the long-term trend over the past two millennia has been towards climatic cooling. "We found that previous estimates of historical temperatures during the Roman era and the Middle Ages were too low," says Esper. "Such findings are also significant with regard to climate policy, as they will influence the way today's climate changes are seen in context of historical warm periods."

For the first time, researchers have now been able to use the data derived from tree-rings to precisely calculate a much longer-term cooling trend that has been playing out over the past 2,000 years. Their findings demonstrate that this trend involves a cooling of -0.3°C per millennium due to gradual changes to the position of the sun and an increase in the distance between the Earth and the sun.

"This figure we calculated may not seem particularly significant," says Esper. "However, it is also not negligible when compared to global warming, which up to now has been less than 1°C. Our results suggest that the large-scale climate reconstruction shown by the Intergovernmental Panel on Climate Change (IPCC) likely underestimate this long-term cooling trend over the past few millennia."

Source: http://www.sciencedaily.com/releases/2012/07/120709092606.htm

Misrepresent opponent’s position/product or go

after weaker opponent

Straw Man

An argument that

presents two alternatives, both claimed to be bad for someone or position.

False Dilemma

When the premise is based on the very

conclusion that is at issue.

Begging the Question

A defendant pleads: “Your Honor, I plead the 5th [Amendment to the Constitution].” Every American is granted the right to not incriminate himself

in a court of law.  If a citizen chooses to speak, he can clarify his innocence (or guilt) rather than leaving that decision in the minds of a jury or judge.  

“Pleading the Fifth,” however, implies guilt in many people’s eyes, including those in the jury box.  Why would someone NOT speak up for himself if he were truly innocent?  During the O.J. Simpson trial: O.J. never took the witness stand to defend himself or to implicate another suspect.  Why not?  The mother of his children was murdered, he is the sole suspect, and he has nothing to say? 

Many people questioned his innocence as a result.

Evading the Issue

Ad Hominem

“Paul Ryan was born in Transylvania. He feasts on the blood of children. He has no soul and will burn in hellfire and damnation 4 etermity. (sic)”

- Roseanne Barr, On the night of Paul Ryan’s speech to the Republican National Convention August 29, 2012 Roseanne Barr became the candidate of the socialist Peace and Freedom Party after being soundly defeated in the Green Party.

Barr, who is running for the presidency with Cindy Sheehan, warned of "Jewish mind control" last week and said patrons of Chick-fil-A "deserve" to get cancer.

Tu Quoque or Two Wrongs Make a Right

Jane: "Did you hear about those terrorists killing those poor people? That sort of killing is just wrong." 

Sue: "Those terrorists are justified. After all, their land was taken from them. It is morally right for them to do what they do." 

Jane: "Even when they blow up busloads of children?" 

Sue: "Yes.“

OR: I borrow your pen and don’t give it back, reasoning that if you had taken mine, you wouldn’t have given mine back.

Non Sequitur

Equivocation

- when a term or expression is used to mean one thing in one place and another thing in another place

To take the lack of evidence, and thus the lack

of refutation, as justification for believing something is true.

Appeal to Ignorance

Premise: Delaney doesn't have an alibi that proves he wasn't at the scene of the crime.

Conclusion: Delaney was at the scene of thecrime.

So…Delany’s going to the pokey…

Paycheck advances – low monthly payments (ignoring high total

costs) in this case 117%...hm… on $5000 that’s $10850.

Fallacy of Composition: AKA salesman’s fallacy

Slippery Slope

Broken Window Fallacy

draws a general rule from a single, perhaps

atypical, case. It is the reverse of a sweeping generalization.

Hasty Generalization

(1) My Christian / atheist neighbor is a real grouch.Therefore:(2) Christians / atheists are grouches.

This argument takes an individual case and draws a general rule from it, assuming that all Christians or atheists are like the neighbor.

The conclusion that it reaches hasn’t been demonstrated, because it may well be that the neighbor is not a typical Christian or atheist, and that the conclusion drawn is false.

post hoc ergo propter hoc = after this, therefore because of this 

Correlation does not

imply causation.

Students are like nails. Just as nails must be

hit in the head in order to make them work, so must students.

An argument by analogy is only as strong as the comparison on which it rests. 

False/Weak Analogy

“Millionaire job creators are like unicorns. They’re impossible to find, and they don’t exist… Only a tiny fraction of people making more than a million dollars, probably less than 1 percent, are small business owners. And only a tiny fraction of that tiny fraction are traditional job creators…Most of these businesses are hedge fund managers or wealthy lawyers. They don’t do much hiring and they don’t need tax breaks.”

In 2009,there were 27.5 million businesses in the United States, according to Office of Advocacy estimates.

Small firms with fewer than 500 employees represent 99.9 percent of the total.

Small businesses employ about half of U.S. workers. 

Small firms accounted for 65 percent (or 9.8 million) of the 15 million net new jobs created between 1993 and 2009. 

“Millionaire tax filers earn almost a quarter trillion dollars from their businesses. They must hire hundreds of thousands of employees to do so.”

Source: IRS’s Table 1.4 ‘Sources of income, adjustments, and tax size of adjusted gross income, 2009’

The evidence shows that millionaires are an ever-changing group of people who tend to share some common but desirable traits—they are married two-earner couples, who are older, well educated, and America’s business owners.

A clue which is misleading or distracting from

the actual issue 

Mostly used to claim that the argument of another person is not relevant to the issue being discussed

In mystery fiction, a clue or lead that turns out to be irrelevant to the solution of the mystery

Red Herring

Red Herring Example

The character of Sebastian Nightwine, who, rich and bigoted, and almost certainly the murderer of his own father, nevertheless, is a distraction from the real murderer.

Even if you could count on thinking correctly

100% of the time, other people don’t.

Often they are completely unaware of their errors in thinking – or simply don’t care.

In order to make smart choices in your life, critical thinking is necessary. Period.

A Final Word