#20 - Selena claims to have psychic powers. So if we

[Dancingbambarina]

Hi,

I am not understanding the ABSENCE issue very well. I don't understand how conditionality is used here. In the LRB, we have examples but they are basic compared to this. This is torturous becasue I am used to there being A, then B in the conclusion, then the correct AC being A leads to B. This is different. The kids would say, "this hits different". I must admit, it sure does.

DB

[Dancingbambarina]

Also, in Jon's excellent description, he acknowledges whether OR NOT the claim is true, but not whether it's possible OR IMPOSSIBLE. Why is the first WHETHER descriptive of the claim being true or false, and the second one just of POSSIBILITY, not also IMPOSSIBILITY?

Thanks again!

[Adam Tyson]

The author of the argument has set up a biconditional relationship:

Selena's Claim is True Psychic Powers are Possible

Obviously, if she has them, then it's possible to have them. That's a self-proving statement. But to prove that it goes both ways, we also need to know the reverse. We need to know that if she doesn't have the powers, then it isn't possible to have them; if it's possible to have them, she does.

So, it's about both the possibility of someone having them AND about Selena actually having them. The two are tied together in the argument, and to prove that we need an answer that guarantees that the two go hand-in-hand.

[jackieb]

How do we know the author also includes the negative implication in the conclusion? I read this as simply "if she has the powers, we will know it is possible." Btw, I understand how the AC would justify it if there is the hidden negative implication in the assumption but I did not pick up on the hidden "or not". Does anytime someone says "whether" on the LSAT, there is an implied "or not"?

[Jeff Wren]

Hi jackie,

There are several definitions for the word "whether," but the one most relevant to this stimulus is "expressing an inquiry or investigation." In this usage, there is an implied "or not" even if the sentence doesn't explicitly state it.

For example, the statement, "I will look outside to see whether it is raining" means "whether or not it is raining" because both outcomes are possible.

In this stimulus, the statement, "if we find out whether Selena's claim is true" allows for either an affirmative or negative answer to this question. Finding out that her claim is not true does determine whether (or not) her claim is true.