Lawgic Flashcards
(25 cards)
Rule: Sufficient satisfied?
…Necessary must be as well. (Conditional argument)
How to simplify arguments?
1)Kick ideas up into the domain.
2)Transform embedded conditionals into conditionals with conjunctive sufficient conditions.
3)Use the Rule + Exception framework.
Rule: If the Necessary failed, what does that say about the sufficient?
…sufficient must be as well. (Contrapositive argument)
Rule: What is Chaining conditionals?
Merge together the same symbol to create a chain.
Trap: The sufficient condition failed, what does that say abt the necessary?
…it yields no information about the necessary.
Trap: The Necessary is satisfied, what does that say abt the sufficient condition?
It yields NO information about the sufficient.
Trap: Which should not be confused for the other?
Do not confuse sufficiency for necessity!
Conditional Indicators: Group 1
Indicates sufficient:
if,
when,
where,
all,
the only,
every,
any
Conditional Indicators: Group 2
Indicates necessary:
only,
only if,
only when,
only where,
always,
must
Conditional Indicators: Group 3
Negate then make sufficient:
or,
unless,
until,
without
Conditional Indicators: Group 4
Negate then make necessary:
no,
none,
not both,
never,
cannot
What is:
A → B
(x)A
________
(x)B
Conditional Argument
Formal Argument #1
What is:
A → B
(x)/B
________
(x)/A
Contrapositive Argument
Formal Argument #2
What is:
A → B → C
________
A → C
Conditional Chaining
Formal Argument #3
What is:
A ←s→ B → C
________________
A ←s→ C
Some before All
Formal Argument #4
What is:
A —m→ B → C
________________
A —m→ C
Most Before All
Formal Argument #5
What is:
A —m→ B
A —m→ C
________
B ←s→ C
Two Split Mosts
Formal Argument #6
What is:
A → B
A —m→ C
________
B ←s→ C
#6 Modified
Formal Argument #7
What is:
A → B
x/A
_________
x/B
Logical flaw:
Denying the sufficient condition (Confusing S for N)
What is:
A → B
xB
________
xA
Logical Flaw:
Affirming the Necessary Condition
What is:
A —m→ B
_________
B —m→ A
Logical Flaw:
“Most” statements are not reversible.
What is:
A → B —m→ C
_________
A ←s→ C
Logical Flaw:
All before Most
What is:
A → B —s→ C
_________
A ←s→ C
Logical Flaw:
All before Some.
What is:
A —m→ B —m→ C
__________________
A ←s→ C
Logical flaw:
Most Before Most
