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Reference: The Powerscore Logical Reasoning Bible; Chapter Six, pgs. 115-170Some Common Confusion over Conditional Reasoning Concepts Clarified...I Hope1. The sufficient condition NEEDS, REQUIRES and GUARANTEES the occurrence of the necessary condition
Paris Hilton REQUIRES parties. If Paris Hilton has a free evening, then she will attend a party.
PH ---> P2. The necessary condition does NOT require the occurrence of the sufficient condition
orThe necessary condition may or may not occur proximate to the occurrence of the sufficient condition
A party may occur with or without Paris Hilton. Some parties are not to Paris's taste. A 5 year old's party would probably not indicate the occurrence of Paris Hilton's presence. A retirement party for an insurance company salesman would probably not indicate the occurrence of Paris Hilton.3. Think of the common uses of the terms when evaluating statements for the presence of a conditional relationship.
Sufficient = Enough
Necessary = Required for...
B is necessary (required) but not sufficient (enough) for A
A party is necessary (required) for Paris Hilton, but it's not sufficient (enough); Paris also requires designer clothes, paparazzi attention, a vapid sidekick as an accessory, a teacup dog wearing clothing as an accessory (Liz has a new idea for an avatar!), the use of the phrase: "That's hot", a Bentley, $$$$$, and many, many, many, more things.4. The sufficient condition does not cause, but indicates or signals the occurrence of the necessary condition.
There is no cause and effect relationship between the sufficient condition and the necessary condition. The necessary condition can occur before, concurrent with, or after the sufficient condition.
5. Memorizing lists of conditional indicator words is necessary but not sufficient
You must memorize the indicator words, but you need to understand the relationship between the sufficient and necessary conditions. Only one indicator word may be present, so you need to have a full understanding to identify conditionality.
If Paris Hilton is in town, one can expect a hot party will happen.
"One can expect" is not any list of indicator words but it introduces the necessary condition.
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