Philosophy1001

Premises is intended to make likely/probable. But not guarantee the truth of its conclusion.

Ex : Every lawyer that I have met has been aggressive. Since your blind date tonight is a lawyer, she will probably be aggressive.

• 1. Sample Size?
• 2. Representatives.

If the truth of its premises is intended to guarantee the truth of its conclusions.

• Ex : All humans are mortal.
• Sally is a Human.
• So, Sally is mortal.

• 1. Validity 
• 2. True Premises.
• 3. All relevant information is included.

A

Statement where its truth depends on something other than itself.

A • ~ A

Statement that's necessarily FALSE.

A v ~ A

statement that's necessarily TRUE.

• If P then Q
• Q
• ∆ P

Invalid

• Ex: If it rains, the ground will be wet.
• The ground is wet.
• So, it's raining.

• If P, then Q.
• ~ P
• ∆ ~ Q

Invalid

• Ex : If the birds are chirping, it's Spring.
• The Birds are not chirping.
• Therefore, it's not spring.

• P v Q
• ~P 
• ∆ Q
• *vice versa*

Valid

• Ex : Either he'll buy a Honda or a Harley.
• Didn't buy a Honda.
• So, he bought a Harley.

• If P, then Q
• If Q, then R
• So, if P, then R.

Valid

• Ex : If I sell my car, I'll get $1500.
• If I get $1500, I can go to Spain.
• So, if I sell my car, I can go to Spain.

• If P then Q
• ~ Q
• ∆ ~ P

Valid

• Ex : If she really loved you, she would have agreed to marry you.
• She didn't agree to marry you.
• She didn't love you.

• If P, then Q.
• P.
• Q.

Valid

• If it's Wednesday, then she wears blue.
• It's Wednesday.
• So, she'll wear blue.

If all of its premises are true, then the conclusion must be true.

All true premises and a false conclusion.

When we infer front the fact that all A's observed so far are Bs to the conclusion that all As whatsoever are Bs.

• 1. Invalid Inference : drawing conclusions not sufficiently supported by evidence.
• 2. Questionable Premises : Accepting premises that we should doubt
• 3. Suppressed Evidence : Neglecting relevant evidence.

- committed when we accept the conclusion of an argument solely on the basis that "so and so" said so, does so, believes so etc. One person or many.

• - Committed when we are persuaded to accept the conclusion of an argument that contains self-contradictory statements that contradict each other.
• I'm saying A, but I'm also not saying A.

• - To negatively represent another's argument, beliefs, practices, etc. so that they can easily be refuted. 
• - To mention of underscore only the weak or negative aspects/elements of an argument, product or practice and ignore the strong points.
• - Goes after the naturally weaker opponent, argument, product and position. Level 20 vs level 2.

- When forces to choose between two UNDESIRABLE alternatives.

• - when two options are given and one option is considered undesirable, so the other option is taken. 
• P v Q
• ~ P 
• Q

• - 1. Going between the horns : saying that there's at least a 3rd alternative. Attacks the 1st premise.
• - 2. Grasping the horns : challenging one or more of the remaining premises. Attacks the 2nd premise.

• - To leave the issue/question at hand unaddressed. Leaves it unanswered. 
• - 1. Using the same proposition as both the premise and conclusion. Being redundant, but using different words.
• - 2. To use a premise where truth presupposes or requires that we already know the truth of the conclusion. (Circular Reasoning)
• - 3. Evading the issue (explained @ next slide)

- Technically answers the question, but still evades the issue.

- when a premise that is not believable is spotted in an argument and none of these more specific labels apply.

• - Failing to bring relevant evidence to bear on an argument. 
• Example : advocates on both sides of the debates about the merits of "three strikes, and you're out" laws who slight sensible arguments and objections of their opponents"

- Accepting a token gesture in lieu of the real thing.

- of attacking his opponent rather than his opponent's evidence and arguments.

• P : Person A makes Claim X
• P : Person B makes an attack on person A.
• Con : Therefore, A's claim is false.

- a person rejects a claim simply because it is pointed out that people she dislikes accept the claim. This sort of "reasoning" has the following form:

• P: It is pointed out that people person A does not like accept claim P.
• Con : Therefore P is false

- Those who try to justify a wrong by pointing to a similar wrong perpetrated by others. "Tu Quoque"

• P: It is claimed the person B would do X to person A.
• Con : It is acceptable for person A to do X to person B.

- Committed when a wrong is justified on the grounds that one other person or group, but rather lots of, or most, or even all other do the same sort of thing. 

• P :X is a common action.
• Con : Therefore X is correct/moral/justified/reasonable, etc.

P :

- When a wrong or an unsuitable practice is justified on grounds that it follows a traditional or accepted way of doing things.

• P : X is old or traditional
• Con : Therefore X is correct or better.

- "It dos not follow" refer to reasons or premises that are irrelevant to a conclusion when the error doesn't fit a narrower fallacy category such as ad hominem or two wrongs don't make a right.

Doesn't fall on both ad hominem or two wrongs make a right.

- an argument when used to mean one thing in one place and another thing in another.

• - Taking the absence of evidence, and thus absence of refutation, as justification for believing that it's true.
• "your inability to show that I'm right proves that I'm right."

- committed when someone assumes that a particular item myst have a certain property because all of its parts have that property. 

ex : Moving from part (P) to whole (Con).

• P : Individual F things have characteristics A, B, C etc.
• Con : Therefore, the (whole) class of F things has characteristics A, B, C, etc.

- committed when we assume that all of the parts of an item have a particular property because the item as a whole has it. 

ex : Moving from whole (P) to parts (Con)

• P: The whole, X, has properties A, B, C, etc.
• Con : Therefore the parts of X have properties A, B, C, etc.

- Committed when one assumes without proof or further justification that the occurrence of an event or action will lead through a series of connections to an inevitable conclusion.

- committed when we accept a conclusion based upon evidence that, while relevant to the conclusion, is not sufficient by itself to warrant acceptance of the conclusion. Reasons are relevant, but not enough.

- Drawing conclusions about a population on the basis of a sample that is too small to be reliable measure of that population.

- when we reason from a sample that isn’t sufficiently representative. Also known as biased statistics.

Example : Using chimps, gorillas, lemurs, tarsiers and so forth is not representative of all Homo sapiens.

• - labeling A as the cause of B on evidence that is insufficient, negative, unrepresentative, or in serious conflict with well-established high-level theories.
• 1. X caused Y
• 2. Y caused X
• 3. X and Y are both the effects of a common cause, Z.

• • Guilt of confusing cause and effect 
• • Guilt of neglecting a common cause
• • Guilt of post HOC reasoning. “after this, therefore before this.”

- when we conclude the from the observed similarity of two or more items in some respects to their similarity in another. a.k.a faulty comparison.

*don't forget to mention how/why it's a questionable analogy and include a reason.*

• - perfectly good statistics that are questionable without further support.
• - You question where these statistics are from.

• - taking good statistics and manipulating it.
• Troubling in two reasons :
• 1.) inability of so many people to understand the significance of this statistic.
• 2.) ability to bamboozle the rest of us.

• - Polls can be misleading because of...
• 1. The way in which a question is asked influences the answers.
• 2. They ask the wrong questions.
• 3. Respondents don’t want to appear ignorant.

The temptation to charge inconsistency, but making a given statement at one time and one that contradicts it at a later time does not indicate inconsistency; we may have, and express, good grounds of changing our minds. 

example : “I used to believe that women are not as creative as men, because most of the intellectually productive people I knew about were men; but i’ve changed my mind. 

There can also be false charge of fallacy against analogy. When we accuse someone of perpetrating a questionable analogy, when their intent is not to prove something, but merely, via analogy, to explain it.