LR Bible Page 163 # 5 Forum

[Ssoto0055]

On this problem is answer C properly diagrammed as ~C -> ~SS ? If I understand this correctly the "no" at the beginning negates the necessary condition (SS) and the "unless" negates the sufficient condition (C). So why isn't this a contrapositive instead of a mistaken reversal as the book says in the answer a few pages later?

Thanks.

[smc44]

On this problem is answer C properly diagrammed as ~C -> ~SS ? If I understand this correctly the "no" at the beginning negates the necessary condition (SS) and the "unless" negates the sufficient condition (C). So why isn't this a contrapositive instead of a mistaken reversal as the book says in the answer a few pages later?

Thanks.

Answer C, using their abbreviations would be ~AC -> SS. This is translated in English to "if the politician does not avoid censure (i.e. he is censured), then he was known to be involved in a serious scandal."

[smc44]

On this problem is answer C properly diagrammed as ~C -> ~SS ? If I understand this correctly the "no" at the beginning negates the necessary condition (SS) and the "unless" negates the sufficient condition (C). So why isn't this a contrapositive instead of a mistaken reversal as the book says in the answer a few pages later?

Thanks.

Upon further review, it seems like you are confusing the Unless equation that Powerscore uses. Whatever is modified by the "unless" becomes the necessary condition, and the other term is negated and becomes the sufficient condition. So in this answer choice "unless" modifies SS (he or she is known to be involved in a serious scandal) and the other term is negated and becomes the sufficient condition ~AC (Politician is censured). So the answer choice is diagrammed as ~AC --> SS. Does that help?

[Ssoto0055]

I read earlier in the chapter where if the word "no" is at the beginning of a state such as in the "No robot can think" statement, the "No" actually modies the necessary condition. So in answer choice C it doesn't apply because of the unless? That is where my confusion is.