LESSON 4: Validity or Strength of Arguments Flashcards
What are the two kinds of arguments discussed in this lesson?
Inductive and deductive arguments
What does a deductive argument aim to provide?
Decisive support for its conclusions
What are good deductive arguments characterized as?
Valid and sound
What does an inductive argument aim to provide?
Probable support for its conclusions
What are good inductive arguments characterized as?
Strong and cogent
Fill in the blank: A deductive argument is one where the premises ______ the conclusion.
guarantee or necessitate
Fill in the blank: An inductive argument is one where the premises make the conclusion ______.
probable
What is the structure of a deductive argument?
If the premises are true, the conclusion must be true
What is the structure of an inductive argument?
If the premises are true, the conclusion is probably true
What is ‘inference to the best explanation’ also known as?
Abduction
What type of arguments does deduction include?
- Mathematical arguments
- Logical arguments
- Arguments from definition
What type of arguments does induction include?
- Arguments from analogy
- Arguments from qualified authority
- Causal inferences
- Scientific hypothetical reasoning
- Extrapolations from samples
True or False: An argument can be true or false.
False
What is a valid argument structure?
An argument structure where the truth of the premises guarantees the truth of the conclusion
What is a sound argument?
A valid argument with true premises
What is an unsound argument?
An argument that is either invalid or has at least one false premise
What is truth in relation to propositions?
A true proposition accurately represents reality
Fill in the blank: An inductive argument is strong if the premises, if true, would demonstrate that the conclusion is ______.
likely to be true
What term is used for inductive arguments that have all true premises and strong support?
Cogent
What is the opposite of a cogent argument?
Uncogent
True or False: All sound arguments are valid.
True
True or False: All valid arguments are sound.
False
What is the difference between validity and truth?
Validity is about the structure of the argument, while truth pertains to the propositions within it
What happens if an argument is valid and has all true premises?
The conclusion must be true
What does a strong inductive argument provide?
More or less strong reason for accepting the conclusion
What is the conclusion of a valid argument if the premises are true?
The conclusion must necessarily be true
Fill in the blank: A deductive argument is valid if it has a ______ structure.
valid
What is the definition of Truth in arguments?
Propositions are true if they accurately represent what is the case, otherwise they are false.
What does Strength refer to in an inductive argument?
In an inductive argument, the truth of the premises would make the conclusion probably true.
What is Cogency in the context of inductive arguments?
An inductive argument is cogent if it is strong and all its premises are true.
What is the formula for a Cogent Argument?
All True Premises + Strong Inductive Support = Cogent Argument.
Can an inductive argument be valid?
No, an inductive argument cannot be valid.
Why can’t an inductive argument be valid?
Because a valid argument guarantees the truth of the conclusion with 100% certainty, while an inductive argument only justifies its conclusion to some level of probability less than 100%.
What does Soundness mean in deductive arguments?
A deductive argument is sound if it has a valid structure and all its premises are true.
What is the difference between Validity and Soundness?
Validity only concerns the structure of an argument, but soundness requires both validity and true premises.
What is the definition of a Valid argument?
In a valid deductive argument, the truth of the premises would make the conclusion necessarily true.
What characterizes a Strong inductive argument?
In a strong inductive argument, the truth of premises would make the conclusion probably true.
What is an example of a deductive argument?
If Jones is a baseball player, then Jones is an athlete. Jones is a baseball player. Thus, Jones is an athlete.
What terms categorize the argument: ‘Everyone who lives in Los Angeles lives in California. Everyone who lives in California lives in the United States. Therefore, everyone who lives in Los Angeles lives in the United States.’?
Valid, Sound.
What terms categorize the inductive argument: ‘In the past, it has snowed in Alaska every winter for the last 100 years. Therefore, it will probably snow in Alaska next winter.’?
Strong, Cogent.
Fill in the blank: A deductive argument is sound if it has a valid structure and all its _______.
premises are true.
Fill in the blank: A cogent argument is strong and has _______.
true premises.
What describes the argument: ‘All cats have four legs. That animal is a cat, therefore it has four legs.’?
Deductive.
What describes the argument: ‘All the whales I saw were gray. Therefore all whales are gray.’?
Inductive.
What describes the argument: ‘The vast majority of Americans own yachts. Since Carla is an American, she probably owns a yacht.’?
Weak.
What describes the argument: ‘All the students who passed the midterm exam passed the final exam as well. Ethan passed the final exam. Therefore, Ethan passed the midterm exam.’?
Invalid.
