LR Bible Weaken Q. Pg 267. Example 5. Answer Choice A.

[dsamad]

Hi,

I would truly appreciate your help in further explaining the reason that answer choice A weakens the argument. I am not asking because I don’t understand the reason behind choosing answer choice E. Instead, I know E is indifferent to the argument, but I also see A as indifferent. Answer choice A provides that the necessary doesn’t occur while the sufficient occurs, i.e. the 30% tax is exceeded while the incentive is not deterred yet (and thus the value system maintained). Having or not having the necessary does not affect the sufficient. So why was this answer considered to weaken the argument?

Thank you in advance.

Regards,

[Adam Tyson]

The key is in comparing the numbers, dsamad. The conclusion is saying that nations must cap their upper tax bracket at 30%, and answer choice A is saying "actually, the impact of higher taxes doesn't kick in until you hit 45%." The implication of answer A is that a nation could have a tax bracket somewhere above 30% and still be fine, so long as it doesn't get as high as 45%. 39%, for example, would be fine, and would have no effect on technological innovation. That ruins the conclusion of the argument!

By the way, to some extent you answered your own question here. You said:

Answer choice A provides that the necessary doesn’t occur while the sufficient occurs

That for sure weakens a conditional claim! If I said "if I drive a Corvette, chicks will dig me," and you respond "you can buy a Corvette if you want, but chicks still won't dig you because you are a silly old fart," then you have weakened my claim by showing that my alleged Sufficient Condition can occur while my supposed Necessary Condition does not. My Sufficient Condition is not actually sufficient, so I am wrong.

[dsamad]

Thank you so much Adam!