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General questions relating to LSAT Logical Reasoning.
 Foti
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#76241
It is irrational to refuse to give to a worthy charity simply because one does not feel like doing so.
Make sure your negation makes sense to you: in other words, it’s OK to give to a worthy charity simply because you feel like it.

Hi! The original statement here was "It is not irrational to refuse to give to a worthy charity simply because one does not feel like doing so". I have no problem understanding that the negation of this statement would be "it is irrational to refuse to give to a worthy charity simply because one does not feel like doing so". However, I do not understand how that negation is synonymous with Nikki's latter clarification that conceptually it means "it’s OK to give to a worthy charity simply because you feel like it." In my mind, if you hold the belief that "it is irrational to refuse to give to a worthy charity simply because one does not feel like doing so" it enables the possibility to also have the belief "it’s OK to give to a worthy charity simply because you feel like it", but it doesn't necessarily mean the same thing.
 caroline222
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#83102
Hi powerscore,

I read everything above, but I am still kind of struggling with negating answer choices that are conditional. I know that the goal is to show that the sufficient condition can occur without the necessary condition, but I don't always know how to construct that in my head.

For instance, I saw this answer choice on a problem: If the town officials did not follow their own advice then that advice is not worth following.
I negated this to say: The advice is worth following even if the town officials did not follow their own advice.
Is this correct?

Do you have any tips for increasing speed with negating conditional statements?

Thank you!
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 Dave Killoran
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#83116
caroline222 wrote: Sat Jan 09, 2021 9:34 pm Hi powerscore,

I read everything above, but I am still kind of struggling with negating answer choices that are conditional. I know that the goal is to show that the sufficient condition can occur without the necessary condition, but I don't always know how to construct that in my head.

For instance, I saw this answer choice on a problem: If the town officials did not follow their own advice then that advice is not worth following.
I negated this to say: The advice is worth following even if the town officials did not follow their own advice.
Is this correct?

Do you have any tips for increasing speed with negating conditional statements?

Thank you!
Hi Caroline,

In time, you will find negating conditional statements is actually fairly easy, but you have to follow a simple formula for it. Once you see how that works and try it a few times, it will get much much faster for you :-D

Here's the basic formula: whatever they say is necessary, isn't. That doesn't mean it can't ever occur, it just means that it's not required. Let's look at a few examples:

  • "To lower CO2 emissions, we must use wind power." — Here, the conditional statement indicates that "using wind power" is necessary. So, to negate the statement, simply state that wind power isn't necessary. Because English is so variable, there are many different ways to state that, but here are two that work: "To lower CO2 emissions, wind power is not necessary" and "We can lower CO2 emissions without having to use wind power."
The above example shows how the negation is very direct—it just knocks out the necessity aspect of the necessary condition. Of course, that's stated in a very simple form, but the principle applies even if the conditional statement is a bit more challenging:

  • "People who do not recycle do not deserve tax breaks." — Here, the statement contains a set of negatives, which bothers many people. But the process is still the same. First, the statement can be diagrammed as: Recycle :arrow: Tax Breaks. Now, to negate, we make the necessary condition not necessary any more: People who do not recycle still might deserve tax breaks" (or any of multiple variations).
If you look at that second example, it's very similar to the example you asked about, which would just be a variation on " If the town officials did not follow their own advice then that advice might be worth following." That's basically what you said, so you were right :-D

The real key here is that once you see this process clearly and try it a few times, it gets much faster and easier.

Please let me know if that helps. Thanks!
 caroline222
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  • Joined: Jan 07, 2021
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#83121
Hi Dave,

Thank you so so much for that explanation - it really helps! I think I was very concerned with trying to mix the sentence around so I can use "even if" but I see that it is still very clear when I just negate the necessary without worrying about changing around the sentence!

For negating sentences using the Unless Equation, do you think it is easiest to diagram the sentence in my head first and then negate the necessary?
Ex: I can't watch TV until I finish my homework: watch TV :arrow: finish homework
The negation would be: I can watch TV even if I don't finish my homework.

Can you give a more complex example using without? For some reason I always get tripped up when I see without in a sentence I need to negate.

Thank you again :)
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 Dave Killoran
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#83146
As far as Unless, yes, that's how I do it :)

And Without operates identically to Unless as far as diagramming, so if you can do Unless (and you correctly did above!), Without is the same process!

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