Argument Structure Flashcards
What is an argument?
A conclusion supported by at least one premise.
What is a premise?
Stated facts that are intended to support a conclusion.
What is a conclusion?
Propositions that are supported by a premise
What are some indicators for premises?
Since Because For As After all Moreover In addition Given that
What are some conclusion indicators?
Therefore Thus Hence So As a result Consequently It follows that It is clear that
What are assumptions?
An assumption is not explicitly stated but must be true in order for the conclusion to be inferred from the premises.
What is the three step process for breaking down arguments?
- Locate (and underline) the conclusion
- Find the relevant premises
- Identify any assumptions in the argument
Define the term valid
When the conclusion of an argument can be logically inferred from its premises
When is an argument sound?
If and only if it is valid and has true premises
When is an argument valid?
An argument is valid if and only if the conclusion can be properly inferred from the premises
When is an argument invalid?
If the conclusion cannot be properly inferred from the premises
What is an absolute statement?
A statement that asserts the existence of some fact.
What is a conditional statement?
A statement that asserts the hypothetical existence of a hypothetical relationship between conditions. (If A is met, then B must follow.)
What is a sufficient condition?
A condition that is enough to guarantee that a necessary condition will follow.
What is a necessary condition?
A condition that is required to satisfy the sufficient condition.
What is valid affirmation?
When the sufficient condition is affirmed, the necessary condition is guaranteed to follow logically.
What is the contrapositive?
When a necessary is denied, the sufficient condition must be denied as well. “Bring that thing down flip it and reverse it.”
What is the fallacy of the converse?
An invalid inference that confuses a conditional statement for being reciprocal.
If a then b
If b then a
What is the fallacy of the inverse?
When the sufficient condition is denied, the necessary condition may or may not obtain. (There could be other sufficient conditions that guarantee the same necessary condition) invalid inference
Keywords to recognize sufficiency ?
If When Whenever All Any Each Every
Keywords for necessity
Then Only Only if Only when Needs Requires Must
How will only if occur on the LSAT?
Only if A, Then B
B, only if A
How do you diagram proposition/premises with the words until/ unless/ without/ except?
Replace the words with the phrase if not.
What is the transitive property?
When the necessary condition is similar to the sufficient condition of another conditional statement, they can be combined. A valid inference.
