Flashcards in Arguements Deck (16)

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1

## Assuming that the premises are true is it possible for the conclusion to be false? If it is then the argument is invalid.

### Test for validity

2

## Assuming the premises are true, what degree of probability would they confer upon the conclusion

### Test for probability

3

##
If P then Q

P

Therefore Q

###
Modus ponens (valid)

Affirming the antecedent

4

##
If P then Q

Not P

Therefore not Q

### Denying the antecedent (invalid)

5

##
If P then Q

Not Q

Therefore not P

###
Modus Tollens (valid)

Denying the consequent

6

##
If P then Q

Q

Therefore P

### Affirming the consequent (invalid)

7

## In this form we have a conclusion that puts together information found in the premises.

### syllogism

8

## Arguing for the truth based upon what is generally true.

###
Statistical syllogism

Example: Only about 2% of high school students take philosophy. Tom is a high school student, so he doesn't take philosophy.

9

## An argument involving polling a sample group and arguing that what is true of the sample group is true of the population as a whole.

###
Statistical generalisation

Example: 9 out of 10 Owners said their cats preferred wild mice to birds. Woof is a cat, so he will prefer wild mice to birds.

10

## Relying upon the knowledge or testimony of others when something is beyond our experience and expertise.

###
Argument from authority

Example: I'm not going to eat red meat any more. My doctor said it eventually clogs the arteries and will lead to premature heart disease.

11

## When we believe that there are enough similarities between two things and that what can be said of one can be said of another.

###
Argument from analogy

Example: Stealing from your employer is wrong; it's just the same as stealing from a shop.

12

## Inference to the best explanation, is a method of reasoning in which one chooses the hypothesis which would, if true, best explain the relevant evidence. Abductive reasoning starts from a set of accepted facts and infers to their most likely, or best, explanations.

###
Abduction

Example: the sun appears to move across the sky. The best explanation we have for this is that the earth must rotate. Therefore, the earth rotates.

13

##
If P then Q

If Q then R

Therefore

If P then R

### Hypothetical syllogism (valid)

14

##
Either P or Q

If P then R

If Q then S

Therefore

Either R or S

### Dilemma (valid)

15

##
Either P or Q

If P then R

If Q then R

Therefore

R

### Simplified Dilemma (valid)

16