Help out with this logic!

roranoa
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Help out with this logic!

Postby roranoa » Thu Feb 11, 2010 10:38 am

Ok, this is an inference question that keeps getting me.


-A just government never restricts the right of its citizens to act upon their desires except when acting upon their desires is a direct threat to other citizens.


In this sentence, is it simply impossible to infer anything about "UNjust" governments because it doesn't talk about it?

or can you infer that if a government restricts its citizens' rights even though there is no threat, that government is unjust?


Similarly, if there is such sentence: It is wise to study for the LSAT unless you're a genius.

Would it be right to say that you are unwise if you don't study while you're not a genius?

This is confusing!!

Help me out ppl!

am060459
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Re: Help out with this logic!

Postby am060459 » Thu Feb 11, 2010 10:50 am

-A just government never restricts the right of its citizens to act upon their desires except when acting upon their desires is a direct threat to other citizens.

i see it as, if JGR (just government restricts) --> DT (direct threat to other citizens)

if -DT (no direct threat to other citizens), then -JGR (just government does not restrict)



Similarly, if there is such sentence: It is wise to study for the LSAT unless you're a genius.

Would it be right to say that you are unwise if you don't study while you're not a genius?

your doing a mistaken negation. its suppose to be: if your not a genius then it is wise to study for the LSAT.

am060459
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Re: Help out with this logic!

Postby am060459 » Thu Feb 11, 2010 10:55 am

what PT, section and question is this from? thanks.

roranoa
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Re: Help out with this logic!

Postby roranoa » Thu Feb 11, 2010 11:13 am

am060459 wrote:what PT, section and question is this from? thanks.

PT27 section 4 Q.3

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2807
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Re: Help out with this logic!

Postby 2807 » Thu Feb 11, 2010 11:30 am

I don't have it in front of me but I remember this question. I think you are not finished reading it. That statement alone is not the whole picture...

Aren't you asked next something like, "which answer is consistent with this statement?"

and the correct answer is: A government lets its people buy sports cars, but restricts how fast they can drive them on public streets"...

Is that the question/answer ? Damn, I am studying too much....

I forget how to phrase it, but it is something like this.

dynomite
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Re: Help out with this logic!

Postby dynomite » Thu Feb 11, 2010 11:36 am

roranoa wrote:-A just government never restricts the right of its citizens to act upon their desires except when acting upon their desires is a direct threat to other citizens.

Similarly, if there is such sentence: It is wise to study for the LSAT unless you're a genius.

Would it be right to say that you are unwise if you don't study while you're not a genius?


The use of except/unless can be hard. Think of it as if not instead (ignore the grammar). The "if not" piece then becomes the "if" portion of the if/then statement (but appearing as a negative).

(If that sentence confused you, read it again before going on) Now, just simplify the first sentence. What is it saying? It's saying that, if we're talking about a just government, it never restricts citizen actions if not poses a direct threat to others.

Okay, so let's do this as an if/then statement, with the "if not" at the beginning and negated, and the "never restricts citizen actions" part as the "then" statement. So:

If [strike]actions pose a direct threat[/strike] --> [strike]restrict actions[/strike]

And now, the contrapositive...

If restrict actions --> actions pose a direct threat

-----------

The same applies with "It is wise to study for the LSAT if not genius."

If [strike]genius[/strike] --> wise to study for LSAT

If [strike]wise to study for LSAT[/strike] --> genius

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theZeigs
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Re: Help out with this logic!

Postby theZeigs » Thu Feb 11, 2010 12:21 pm

roranoa wrote:....
or can you infer that if a government restricts its citizens' rights even though there is no threat, that government is unjust?
....


You cannot infer an "UNjust" government, just that a government is not a just government. "Not just" (NOT "unjust) is the logical opposite of "just," in the same way that "not happy" (NOT "sad") is the logical opposite of "happy"). A government can be just, unjust, or some combination in the same way you can be happy or sad or anything...

dynomite
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Re: Help out with this logic!

Postby dynomite » Thu Feb 11, 2010 12:44 pm

theZeigs wrote:
roranoa wrote:....
or can you infer that if a government restricts its citizens' rights even though there is no threat, that government is unjust?
....


You cannot infer an "UNjust" government, just that a government is not a just government. "Not just" (NOT "unjust) is the logical opposite of "just," in the same way that "not happy" (NOT "sad") is the logical opposite of "happy"). A government can be just, unjust, or some combination in the same way you can be happy or sad or anything...


I worry that this is confusing.

The question stem says something about what happens under a "just government."

We don't know anything about what happens under an unjust government, and therefore cannot make any statements about it.

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2807
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Re: Help out with this logic!

Postby 2807 » Thu Feb 11, 2010 1:59 pm

Are you sure you can crowbar in formal logic to anything? Maybe this is just not a formal logic situation. I recall that not all phrases or declarative statements are formal logic. Is this really an if/then/therefore situation?

I'm still waiting to see if it is the question I referred to earlier.

Thanks

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asfasdagdsfawe
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Re: Help out with this logic!

Postby asfasdagdsfawe » Thu Feb 11, 2010 2:34 pm

2807 wrote:Are you sure you can crowbar in formal logic to anything? Maybe this is just not a formal logic situation. I recall that not all phrases or declarative statements are formal logic. Is this really an if/then/therefore situation?

I'm still waiting to see if it is the question I referred to earlier.

Thanks



Yeah, I think you can crowbar in formal logic to anything, so long as you translate correctly, because everything we utter is formal logic, albeit often invalid. Of course, I don't think anyone would recommend doing so for a timed test like the LSAT.

dynomite
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Re: Help out with this logic!

Postby dynomite » Thu Feb 11, 2010 2:46 pm

2807 wrote:Are you sure you can crowbar in formal logic to anything? Maybe this is just not a formal logic situation. I recall that not all phrases or declarative statements are formal logic. Is this really an if/then/therefore situation?

I'm still waiting to see if it is the question I referred to earlier.

Thanks


You make a good point, but it's not "crowbar"-ing in this case. The tipoff is absolute relationships -- they indicate direct causes and effects of certain situations (if/then).

In this case, the indicator words for formal logic are: "never" and "except."

roranoa wrote:In this sentence, is it simply impossible to infer anything about "UNjust" governments because it doesn't talk about it?


Correct.

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2807
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Re: Help out with this logic!

Postby 2807 » Thu Feb 11, 2010 2:52 pm

I think that all "formal logic" can be broken down into an if/then format.

But that does not mean everything fulfills the requirements of formal logic.

Certainly someone on here knows this fundamental question. I recall getting tripped up on trying to break stuff down, only to learn it was not formal logic to start with...

I'm learning too, so I just try to absorb as much as I can. Thanks.

dynomite
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Re: Help out with this logic!

Postby dynomite » Thu Feb 11, 2010 3:09 pm

2807 wrote:I think that all "formal logic" can be broken down into an if/then format. But that does not mean everything fulfills the requirements of formal logic.


I'm not quite sure what you mean by "not everything" meeting the "requirements" of formal logic, but I will say Blueprint Prep does a great job of focusing on this distinction.

According to them, it's very important to understand when to diagram formal logic statements and when to draw pictures instead. Ultimately, this is all about getting to the right answer as quickly as possible on test day -- sometimes you can do that by just keeping an idea of what's going on in your head. Sometimes it's really helpful to break down arguments into shorthand formal logic.

That's why you need to make sure you understand what the indicator words are, and how to diagram statements.

trutherd
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Re: Help out with this logic!

Postby trutherd » Thu Feb 11, 2010 3:16 pm

theZeigs wrote:You cannot infer an "UNjust" government, just that a government is not a just government. "Not just" (NOT "unjust) is the logical opposite of "just," in the same way that "not happy" (NOT "sad") is the logical opposite of "happy"). A government can be just, unjust, or some combination in the same way you can be happy or sad or anything...

I disagree; unjust simply means "not just." They are logical opposites (~just = unjust & ~unjust = just).

You can break this down to formal logic but it's not worth the effort here. The prompt is essentially an "if, then, unless" statement and trying to get the contrapositive and whatnot can be time consuming. All you need to take away is that a just government won't restrict unless they have good reason to (and therefore if they do restrict when they have good reason to it doesn't mean they're unjust). This is exactly what the credited response tells you.

As a rule of thumb (so not without exceptions), [strike]you don't need formal logic in the first 10 questions.[/strike]

EDIT: what I meant to say was you generally don't need to diagram formal logic in the first 10 questions.
Last edited by trutherd on Thu Feb 11, 2010 3:40 pm, edited 1 time in total.

am060459
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Re: Help out with this logic!

Postby am060459 » Thu Feb 11, 2010 3:19 pm

trutherd wrote:
theZeigs wrote:You cannot infer an "UNjust" government, just that a government is not a just government. "Not just" (NOT "unjust) is the logical opposite of "just," in the same way that "not happy" (NOT "sad") is the logical opposite of "happy"). A government can be just, unjust, or some combination in the same way you can be happy or sad or anything...

I disagree; unjust simply means "not just." They are logical opposites (~just = unjust & ~unjust = just).

You can break this down to formal logic but it's not worth the effort here. The prompt is essentially an "if, then, unless" statement and trying to get the contrapositive and whatnot can be time consuming. All you need to take away is that a just government won't restrict unless they have good reason to (and therefore if they do restrict when they have good reason to it doesn't mean they're unjust). This is exactly what the credited response tells you.

As a rule of thumb (so not without exceptions), you don't need formal logic in the first 10 questions.


really? how so? (just curious)

trutherd
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Re: Help out with this logic!

Postby trutherd » Thu Feb 11, 2010 3:35 pm

dynomite wrote:
roranoa wrote:In this sentence, is it simply impossible to infer anything about "UNjust" governments because it doesn't talk about it?

Correct.

Not entirely true. The prompt says "If a government is just it will not restrict unless not restricting would threaten other citizens." So, if actions did threaten other citizens, they could restrict them and still be just.

Since just and unjust are logical opposites, you could conclude something like "if the ability of citizens to act on their desires is restricted by the government even when those actions do not harm other citizens, then the government is unjust."

However, what you couldn't do is say anything about what an unjust government would/wouldn't do (like the answer choices that mention an unjust government). Logically, "unjust government" could be the consequent of a conditional but not the antecedent because its negation (just government) is the antecedent.

trutherd
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Re: Help out with this logic!

Postby trutherd » Thu Feb 11, 2010 3:38 pm

am060459 wrote:
trutherd wrote:
theZeigs wrote:You cannot infer an "UNjust" government, just that a government is not a just government. "Not just" (NOT "unjust) is the logical opposite of "just," in the same way that "not happy" (NOT "sad") is the logical opposite of "happy"). A government can be just, unjust, or some combination in the same way you can be happy or sad or anything...

I disagree; unjust simply means "not just." They are logical opposites (~just = unjust & ~unjust = just).

You can break this down to formal logic but it's not worth the effort here. The prompt is essentially an "if, then, unless" statement and trying to get the contrapositive and whatnot can be time consuming. All you need to take away is that a just government won't restrict unless they have good reason to (and therefore if they do restrict when they have good reason to it doesn't mean they're unjust). This is exactly what the credited response tells you.

As a rule of thumb (so not without exceptions), you don't need formal logic in the first 10 questions.


really? how so? (just curious)

Actually when I reread it now it could be a bit misleading... what I should have said was you don't need to diagram formal logic in the first 10 (as a rule of thumb). The can definitely be questions for which formal logic is useful but they're generally simple enough to solve without diagramming.

Thanks for pointing that out, I'll edit a note

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Re: Help out with this logic!

Postby dynomite » Thu Feb 11, 2010 3:49 pm

am060459 wrote:I disagree; unjust simply means "not just." They are logical opposites (~just = unjust & ~unjust = just).


No, this isn't right -- remember, this is LSAT world, not the real world. Unjust might be the logical opposite of just, but we don't have any information about it. All we know is that if those relationships don't exist the government is NOT just (we know this from the contrapositive).

Think of it like strengthen/weaken. Just because something doesn't strengthen an argument doesn't mean it weakens it -- it could be neutral.

trutherd wrote:"if the ability of citizens to act on their desires is restricted by the government even when those actions do not harm other citizens, then the government is unjust."


No, I don't think so. The key distinction you're talking about is between "unjust" and "not just." A government that is "not just" is not necessarily "unjust."

(Note: what I'm saying to both of you only applies if you're using "unjust" the way it's defined in the dictionary -- a society characterized by injustice. If you're just using it to mean anything "not just," then you're right.)

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klussy
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Re: Help out with this logic!

Postby klussy » Thu Feb 11, 2010 4:17 pm

dynomite wrote:
roranoa wrote:-A just government never restricts the right of its citizens to act upon their desires except when acting upon their desires is a direct threat to other citizens.

Similarly, if there is such sentence: It is wise to study for the LSAT unless you're a genius.

Would it be right to say that you are unwise if you don't study while you're not a genius?


The use of except/unless can be hard. Think of it as if not instead (ignore the grammar). The "if not" piece then becomes the "if" portion of the if/then statement (but appearing as a negative).

(If that sentence confused you, read it again before going on) Now, just simplify the first sentence. What is it saying? It's saying that, if we're talking about a just government, it never restricts citizen actions if not poses a direct threat to others.

Okay, so let's do this as an if/then statement, with the "if not" at the beginning and negated, and the "never restricts citizen actions" part as the "then" statement. So:

If [strike]actions pose a direct threat[/strike] --> [strike]restrict actions[/strike]

And now, the contrapositive...

If restrict actions --> actions pose a direct threat

-----------

The same applies with "It is wise to study for the LSAT if not genius."

If [strike]genius[/strike] --> wise to study for LSAT

If [strike]wise to study for LSAT[/strike] --> genius



I really like the "if not" advice. That's just what I needed to know to keep 'unless' straight in my mind without a few seconds wasted per question. Man, your advice is always on point. *appreciates*

trutherd
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Re: Help out with this logic!

Postby trutherd » Thu Feb 11, 2010 4:19 pm

dynomite wrote:The key distinction you're talking about is between "unjust" and "not just." A government that is "not just" is not necessarily "unjust."

(Note that what I'm saying only applies if you're using "unjust" the way it's defined in the dictionary -- a society characterized by injustice. If you're just using it to mean anything "not just," then you're right.)

The dictionary definition of unjust isn't "a society characterized by injustice." Think about it - could my actions, as an individual, be unjust? Definitely, so "society" has nothing to do with the definition of the word.

dictionary.com wrote:not just; lacking in justice or fairness

Pretty straightforward... What about The Authoritative dictionary?
Oxford English Dictionary wrote:1. a. Of persons: Not acting justly or fairly; not observing the principles of justice or fair dealing.
b. Of actions, etc.: Not in accordance with justice or fairness.

Definition (a) is the applicable one here (I think this may be the source of some of the confusion). A "just government" means that the government is just in and of itself, like a person or other individual entity. Also, you can even just look at the prefix: "un-" simply means "not-".

Moral of the story is that there's no in-between or neutral territory in the middle of just and unjust. The are logical opposites in this context so "not just" and "unjust" are identical.

dynomite
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Re: Help out with this logic!

Postby dynomite » Thu Feb 11, 2010 4:59 pm

klussy wrote:I really like the "if not" advice. That's just what I needed to know to keep 'unless' straight in my mind without a few seconds wasted per question. Man, your advice is always on point. *appreciates*


Happy it helped. :)

trutherd wrote:Moral of the story is that there's no in-between or neutral territory in the middle of just and unjust. The are logical opposites in this context so "not just" and "unjust" are identical.


Eh -- I think we're pretty much arguing about semantics, but I don't think that's the moral of the story.

Generally, I think the moral is that it's best not to transform statements in the LR section: just treat them as "not" something when you're negating. (For example, if you're negating cold, always write it as "not cold," instead of hot. Not cold can mean mild as well.) This does not apply to LG, where sometimes "not" being a member of a group means you're a member of another group.

For the record, here's the first link that comes up in google when you type in "Define:unjust"

# unfair: not fair; marked by injustice or partiality or deception; "used unfair methods"; "it was an unfair trial"; "took an unfair advantage"
# violating principles of justice; "unjust punishment"; "an unjust judge"; "an unjust accusation"
# inequitable: not equitable or fair; "the inequitable division of wealth"; "inequitable taxation"
wordnetweb.princeton.edu/perl/webwn


Also for the record, the second is:

Unjust is an American alternative rock/metal band from the San Francisco Bay Area.
en.wikipedia.org/wiki/Unjust_(band)


SO: Agree to disagree on the definition, but I still say every time you stray from the "not" statements on the LSAT you're unsafe... because you're dangerous.

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roranoa
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Re: Help out with this logic!

Postby roranoa » Thu Feb 11, 2010 5:30 pm

2807 wrote:Are you sure you can crowbar in formal logic to anything? Maybe this is just not a formal logic situation. I recall that not all phrases or declarative statements are formal logic. Is this really an if/then/therefore situation?

I'm still waiting to see if it is the question I referred to earlier.

Thanks



Yes, it is in fact the question you referred to earlier

roranoa
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Re: Help out with this logic!

Postby roranoa » Thu Feb 11, 2010 5:43 pm

Thanks dynomite!

I'll take you're advice!

But I have one more thing that's still bothering me.


If you say: It is not wrong for a government to restrict citizens their rights unless acting upon their rights harm each other.

Then can you say: It is wrong for a government to restrict the rights of citizen even if they don't harm each other.

I guess what I'm asking is, the first sentence is talking about what is "not wrong" for a government to do and the second sentence is talking about what is "wrong" for a government to do.

So, can you infer what is "wrong" for a government from a sentence that talks about what is "not wrong" for a government?


(and one more thing, is "even if" logically equivalent to "if" ?)

dynomite
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Re: Help out with this logic!

Postby dynomite » Thu Feb 11, 2010 6:56 pm

roranoa wrote:If you say: It is wrong for a government to restrict citizens their rights unless acting upon their rights harm each other.


Ah ha, another tricky one. (BTW, I cut out the first "not" -- you had it as "it is not wrong for a government..." which seems like the opposite of what the question said, right?)

Well, first things first -- let's get an "if not" in there:

[*] It is wrong for a government to restrict citizens their rights if not acting upon their rights harm each other.

So now let's flip it around so it makes sense as an (if/then) statement:

[*] if not acting upon their rights harm each other, it is wrong for a government to restrict citizens their rights

Kinda ugly, so clean it up:

[*] If [strike]acting upon rights harm each other[/strike] --> wrong to restrict rights

[*] If [strike]wrong to restrict rights[/strike] --> acting upon rights harm each other

roranoa wrote:(and one more thing, is "even if" logically equivalent to "if" ?)


Ehhhh -- yes, for the most part, but I wouldn't worry about this too much. I've never seen "even if" on an LSAT question I don't think, and if it does appear there's not much to logically be drawn from it.

Here's a really good post from Blueprint Prep (I swear I don't work for them, they just have good online links) about the question of whether to diagram that has 'even if' included:

If you are going to diagram, you need to know that taking the time to diagram will actually lead to some logical conclusion. How do you know? You should only take the time to diagram a question if you have the same term that is used in two different conditional statements.

Until 1976, no responsible veterinarian performed experiments that would lead to the death of innocent lab animals. Since 1990, the practice has become more common and many highly-trained veterinarians have commenced to use lab animals for experiments even if they could lead to the death of the animals, but only if the experiments could contribute to the development of life-saving technologies for humans.

This might be a question that students would be tempted to diagram. We definitely see some key words, like “no” and “only if”. But it would not be helpful to diagram this question. In fact, it would probably cause you to waste time and get the question wrong because you would be focusing on the diagram rather than the big picture. But here you should note that there is nothing in common between the two statements. The terms are all different. We have ‘responsible veterinarians’ and ‘highly-trained veterinarians’ and we have ‘would not perform experiments’ and ‘will perform experiments but only if they lead to important discoveries’. But that means there will be no way to combine the statements to get anywhere. For a question like this, you would be much better just summarizing the question by saying that ‘vets are loosening up on animal testing as long as it has good benefits for humans’.


http://moststronglysupported.com/lsatni ... -question/

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dibs
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Re: Help out with this logic!

Postby dibs » Thu Feb 11, 2010 7:24 pm

this thread is an indication of why the LSAT is a cruel and brutal exam. lawyers, by their very nature, spend long hours pouring over research to develop precedent and argument. during the course of such analysis they no doubt have to infer logical structure as has been demonstrated here.

prospective law students have to do it 24-26 times in 35 minutes.

:P




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