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  • Posts: 17
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Hey guys,

Whenever I do the assumption questions I would eliminate it down to two answer choices. I have the tendency to pick the one that phrases the strongest because when I use the negate method the strongest answer choice seems to make more sense.

How should I avoid this?

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I know that the stronger the answer choice is for suffiencet assumption would be okay but not on necessary assumption?
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Hi Hihither!

You are correct that on sufficient assumption questions (we call them Justify questions), you are looking for an answer choice that is strong enough to prove the conclusion 100%. On necessary Assumption questions, however, you are just looking for something that is necessary for the argument. It doesn't have to prove the argument, it doesn't even need to add to the argument; it just needs to be something that the argument cannot do without. If you're using the Assumption Negation technique correctly, it should be leading you to the correct answer. (Remember that the Assumption Negation technique only works on necessary Assumption questions--don't try to use it on sufficient assumption (Justify) questions!)

Let's use a simple argument as an example:

Argument: My friend is a great tennis player.

An assumption necessary for that argument would be something like:
My friend can hit the ball over the net.

It's not a very strong statement, it doesn't give me anything more than what is necessary for the argument. But if I negate it (My friend CANNOT hit the ball over the net.) it completely destroys my argument. How could my friend be a great tennis player if she can't even hit the ball over the net???

An answer choice that would be sufficient to Justify my argument would be something like:
My friend has won Wimbledon twice.

Wow! If my friend has won an international tennis tournament multiple times then she is definitely GREAT at tennis. It's a very strong statement and I don't need anything else. My argument is proven 100%. Mic drop. If I negate this answer choice (My friend has NOT won Wimbledon twice.) it doesn't really affect my argument. My friend could still be a great tennis player without having won Wimbledon twice.

Hope this helps!

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Hey Kelsey,

I really need some help on approaching the necessary assumptions. i can almost always get sufficient assumption right but not necessary. I know I am supposed to find the supprt and conclusion, then look for the disconnect in terms. I always always pick the strong answer... why?? I don't know how to fix this problem. I use the negation technique too but it doesn't help!
 Jon Denning
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Let me follow up on Kelsey's post to recommend an additional Assumption resource: Dave and I recorded a pair of comprehensive PodCast episodes on both Sufficient and Necessary Assumptions. I think you'll find them quite helpful!

..... Necessary:

..... Sufficient:

Give those a listen and see if they clear things up!
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  • Joined: Dec 12, 2022

I'm having a little bit of difficulty utilizing the Negation Technique on Assumption Questions. So when I negate the answer choice, should I also negate the conclusion and see if it still follows logically? Conceptually I understand that negating the answer choice should destroy the author's conclusion, but when I negate answer choices I'm usually at a loss for what I'm supposed to do next.

Thanks in advance!
 Rachael Wilkenfeld
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Hi Presto,

Great question! The goal of the assumption negation technique is to help you imagine what the argument would be like without the potential assumption. So, when you negate the answer choice, you want to put it back in the argument in the negated form. What happens to the argument with the negated assumption? Does it hurt the conclusion? Does it help the conclusion? Does it have no impact on the conclusion? You are looking for an answer choice that hurts the conclusion of the argument when it's negated.

Let's look at how it would work in a simple argument.

Premise: Socrates is a man

Conclusion: Socrates is mortal

Imagine the following possible answers:

(A) Socrates has two legs
(B) Some men live forever
(C) All men are mortal

If we negate answer choice (A), we get that "Socrates does not have two legs." Putting that back into the argument we'd struggle to connect that fact to the conclusion. Answer choice (A) is an example of a no-impact answer. It doesn't impact the conclusion either way.

If we negate answer choice (B) it would say "no man can live forever." If we insert this negation into the argument, we actually support the conclusion. If no man can live forever, and Socrates is a man, that must mean he's mortal. BUT remember, this is the negation that supports the conclusion. That means this is an incorrect answer choice. The absence of the answer choice helps the argument. The answer choice itself does not help the argument.

If we negate answer choice (C), it would say "not all men are mortal." This would hurt the argument. The only thing we know about Socrates is that he is a man. If not all men are mortal, we can't conclude from the fact that Socrates is a man means he's mortal. This makes it less likely that he's mortal, so it hurts the conclusion. The absence of this answer choice hurts the argument, so this is the answer choice we are looking for.

Overall, I highly recommend trying out the negation technique will all answer choices in practice. You'll get a better sense of what it looks like when the negation has no impact on the argument, when it helps the argument, and when it hurts the argument.

Hope that helps!

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