phil2303intro to logiclogic

logicalfallacies

fallacy

incorrect reasoning in argumentation resulting in

a misconception

informalfallaciesstem from inductive arguments, stem from inductive arguments,

not deductive ones.not deductive ones.

deductiveargumentargumentthe premises provide a guarantee of the

truth of the conclusion. In a deductive argument, the premises are intended to

provide support for the conclusion that is so strong that, if the premises are true, it

would be impossible for the conclusion to be false.

The classic example of a deductive argument:

(1)All men are mortal. (true)(2)Socrates is a man. (true)

Therefore:(3) Socrates is mortal. (true)

inductiveargumentargumentthe premises provide reasons supporting

the probable truth of the conclusion. In an inductive argument, the premises are intended only to be so strong that, if they

are true, then it is unlikely that the conclusion is false.

An example of a strong inductive argument would be:

(1)Every day to date the law of gravity has held.

Therefore:(2) The law of gravity will hold tomorrow.

the majority of our time will consist of

evaluating inductive arguments, and

informal fallacies.

ad baculum ad baculum

ad baculum ad baculum

(fear of force): the fallacy committed when one appeals to force or the threat of force to bring about the acceptance of a conclusion.

The ad baculum derives its strength from an appeal to human timidity or fear human timidity or fear and is a fallacy when the appeal is not logically related to the claim being made. In other words, the emotion resulting from a emotion resulting from a threat rather than a pertinent reasonthreat rather than a pertinent reason is used to cause agreement with the purported conclusion of the argument.

The ad baculum contains implicitly or explicitly a threat. Behind this threat is often the idea that in the end, "Might makes right.""Might makes right." Threats, per se, however, are not fallacies because they involve behavior, not arguments.

‘ad baculumad baculum’ logical structure

person L says accept argument A or event x will happen.

event x is bad, dangerous, or threatening.

therefore, argument A is a good argument.

‘ad baculumad baculum’ example:

Chairman of the Board: "All those opposed to my arguments for

the opening of a new department, signify by saying, 'I resign.'"

‘ad baculumad baculum’ example:

I'm sure you can support the proposal to diversify into the fast food industry because if I receive any opposition on this initiative, I will personally see that

you are transferred to the janitorial division of this corporation.

are there times when ‘ad baculum’ arguments

are not fallacious?

the appeal is not irrelevant when the threat or the force is directly relevant to the conclusion or is,

itself, the subject of the argument.

example:study your notes,

[or] you will fail the test.

ad hominem ad hominem

ad hominem ad hominem (abusive and circumstantialabusive and circumstantial):

the fallacy of attacking the character or circumstances of an individual who is

advancing a statement or an argument instead of trying to disprove the truth of the statement or the soundness of the

argument. Often the argument is characterized as a personal attack.

The personal attack is also often termed an "ad personem argument": the statement or argument at issue is dropped from consideration or is ignored, and the locutor's character or circumstances are used to influence opinion.

"tu quoque" or charging the locutor with "being just like the person" -rather than trying to disprove a remark about someone's character or circumstances, one accuses the locutor of having the same character or circumstances. In other words: “I know my argument is bad- but not as bad as his.”

‘ad hominemad hominem’ logical structure

Person L states argument A.

Person L’s character or circumstance is not satisfactory.

therefore, argument A is not a good argument.

‘ad hominemad hominem’ example:

Francis Bacon's philosophy should be dismissed since Bacon was removed

from his chancellorship for dishonesty.

‘ad hominemad hominem’ example:

Prof. Smith says to Prof. White, "You are much too hard on your

students."

Prof. White replies, "But certainly you are not the one to say so. Just last week I

heard several of your students complaining."

are there situations when ‘ad hominemad hominem’ arguments

should be considered?

Det. Mark FuhrmanDet. Mark Fuhrman

The prosecution’s case against O.J. Simpson,

even with DNA evidence at the crime scene, was

cast into reasonable doubt because of Det. Fuhrman’s character

and past pejorative statements about

African Americans.

ex-post facto statistics ex-post facto statistics

ex-post facto statistics ex-post facto statistics

(past event probability):

This fallacy occurs when we attempt to supply mathematical analysis to events that have

occurred in the past.

ex-post facto statistics ex-post facto statistics

This argument is a great for the assumptions that something ‘supernatural’ or ‘transcendent’ has

taken place in our lives.

It also allows for us to think that we are somehow special, or children of destiny because of certain

events.

ex-post facto statistics ex-post facto statistics

(example).

Today I ran into Johnny Depp on Rodeo Drive while vacationing in LA. Out of all the

thousands of movie stars I could have run into there- I ran into him, my favorite actor!

ex-post facto statistics ex-post facto statistics

(example).

The odds of life evolving from a single cell organism to the complexity of what we see now

is 100 to the 23rd power

(or 100 with 23 zeros behind it) 10000000000000000000000000

complex questioncomplex question

complex questioncomplex questionthe fallacy of phrasing a question that, by the

way it is worded, assumes something not contextually granted, assumes something

not true, or assumes a false dichotomy.  To be a fallacy, and not just a rhetorical

technique, the conclusion (usually the answer to the question) must be present

either implicitly or explicitly.

complex questioncomplex question(examples):

Have you stopped beating your wife?

What religion are you and your family?

Did you commit the murder before or after you bought that drink?.

reading assignments

‘ad nauseam’ ‘ad misericordiam’

‘ad novitum’ ‘ad populum’

ad misericordiamad misericordiam

ad misericordiamad misericordiam

(argument from pity or misery): the fallacy committed when pity or a

related emotion such as sympathy or compassion is appealed to for the sake of getting a conclusion

accepted.

a statement or an argument is sought on the basis of an irrelevant appeal to pity. In

other words, pity, or the related emotion is not the

subject or the conclusion of the argument.

‘ad misericordiamad misericordiam’ logical structure

Person L argues statement p or argument A.

L deserves pity because of circumstance y.

Circumstance y is irrelevant to p or A.

Statement p is true or argument A is good.

‘ad misericordiamad misericordiam’ example:

Oh, Officer, There's no reason to give me a traffic ticket for going too fast because I was just on my way to the hospital to see my wife who is in serious condition to tell her I just lost my job and the car will be

repossessed.

‘ad misericordiamad misericordiam’ example:

Public Schools, K through 12, need to have much easier exams for students

because teachers don't fully realize the extent of the emotional repercussions of the sorrow and depression of the many

students who could score much better on easier exams.

when are ‘ad misericordiam’ ‘ad misericordiam’

arguments not fallacious?

global relief arguments are indeed relevant to the problems raised by a

disaster caused by a tidal wave in Sri Lanka, or a

cholera outbreak in India.

ad nauseam ad nauseam

ad nauseam ad nauseam

(repetition or tautologyrepetition or tautology): the fallacy of using constant

repetition, often in the face of massive evidence against a

contention, to make it more likely to be accepted.

The ad nauseam ad nauseam fallacy is really more of a persuasive tactic rather than a form of logic.

It attempts to persuade an audience (normally in debate-type forums) two ways:1.By wearing down the opposition by repeating arguments that have previously been dealt with in hopes that the opponent simply gives up. 2.By deceiving the audience into thinking that the counter objections have been dealt with (when they really have not).

‘ad nauseamad nauseam’ logical structure

There is no ‘pure’ logical form of the ad nauseam fallacy, in that, it can

take multiple fallacious forms to meet the requirement of repetition.

‘ad nauseamad nauseam’ examples:various factors | psychologypsychology

‘Please sir, I didn’t do it.’‘But this is your knife, Mr. Smith.’

‘Please sir, I didn’t do it.’‘A witness saw you stab Mr. Jones.’

‘Please sir, I didn’t do it.’

‘ad nauseamad nauseam’ examples:various factors | marketingmarketing

‘Get whiter ‘whites’, and redder ‘reds’ from new Clorox laundry detergent.’

are there situations when ‘ad nauseamad nauseam’ arguments

should be considered?

ad populum ad populum

(popular appeal or majority appeal): the fallacy of attempting to win popular assent to a conclusion by arousing the

feeling and enthusiasms of the multitude.

ad populum ad populum

There are many variations that this fallacy can take, but the primary focus

results in two common forms:

‘Snob Appeal’the fallacy of attempting to prove a conclusion by appealing to what an

elite or a select few (but not necessarily an authority) in a society

thinks or believes.

(least common form, very close to ad verecundiam)

‘ad populumad populum’ (snob) logical structure

Person L says statement p or argument A.

Person L is in the elite.

Statement p is true or argument A is good..

""BandwagonBandwagon““the fallacy of attempting to prove a

conclusion on the grounds that all or most people think or believe it is

true.

‘ad populumad populum’ (band) logical structure

Most, many, or all persons believe statement p is true.

Statement p is true..

‘ad populumad populum’ example:

Gatorade.It is the official sports drink of the

NFL.

‘ad populumad populum’ example:

It is well recognized by most persons that the present technological

revolution has affected the ethical basis of the nation's institution of education.  Since this belief is so

widely held, there can be little doubt of its accuracy.

are there times when ‘ad populum’ arguments

are not fallacious?

to remark that most physicians believe that a high fat diet is

unhealthy, so that it follows that persons who have a high fat diet

should change their eating habits, is to make a legitimate appeal.