I understand this and the previous bc he used star wars again making the translation easier to dissect. Wording should be reworked on both but if you are confused on the language, he is saying the second example is an incorrect translation into lawgic, but because of that, it does make it a valid argument, however that is NOT what the statements are saying and you will pick a wrong answer.
I don't understand the last paragraph "The only problem is that you made up your own premise B -> A. The actual premise is A -> B. You confused sufficiency for necessity."
The rest of the lesson makes sense, but I'm totally lost when I read that. Maybe make a video or remove/clarify that paragraph? I don't see what that really adds here.
Valid conclusion: Only dogs play outside. Blanche plays outside. Therefore, Blanche is a dog.
Invalid conclusion: All dogs play outside. Blanche plays outside. Therefore, Blanche is a dog.
In the invalid conclusion, Blanche could be a part of another group since it does not explicitly state that you have to be a dog to play outside. She could be human, a cat, etc.
Ok so I also found this lesson confusing. What I think the key take away here is that just because the necessary condition is true tells us nothing about the sufficient condition. That's it.
My example:
All moms use the kitchen. I use the kitchen. Therefore, I am a mom
Lawgic:
Moms -> use kitchen
I KITCHEN
--
I MOM
This is Invalid. WHY? Because I'M NOT A MOM. I AM A SINGLE DUDE. Just because I am using the kitchen does that mean I am a mom? NO!
If you thought me using the kitchen meant I'm a mom you are confusing sufficiency for necessity. You are saying that using the kitchen is SUFFICENT for being a mom. you are saying "All those who use the kitchen are mom".
AFFIRMING THE NECESSARY CONDITION TELLS YOU NOTHING ABOUT THE SUFFICIENT CONDITION
All we know from the stimulus is that All moms use the kitchen.
Mom = Sufficient
Using kitchen = Necessary
If I affirm the necessary condition by saying "I use the kitchen" does that tell you anything about if I am a mom or not?
If the necessary condition is satisfied, it yields no information about the sufficient condition. The sufficient condition could be true or could be false.
"All" is from group 1-necessity conditional indicators, where what follows immediately after the indicator, in this case "all", is the necessary condition. So, lawgic would be:
All Jedi use the Force.
J -> F
Dooku use force:
D -> F
Dooku is Jedi:
D -> J. This conclusion is not valid from the given premise.
In case of "only", its from group 2-sufficiency conditional indicators. What follows immediately after the indicator, "only", is the sufficient condition. So, lawgic would be:
Only Jedi use the Force.
F -> J
Dooku uses the Force.
D -> F
Chaining conditionals:
D -> F -> J
D -> J
We can infer from the above that Dooku is Jedi, which is the conclusion in the argument.
What has made this easier for me is realizing that all is not the same as only. All refers to everything of a certain group. Only is more strict about the rules.
All dogs drink water. Other animals can drink water too.
ONLY dogs drink water. No other animals drink water.
I am also confused by this but I am a little new to studying for this oldest trick in the book that keeps kicking my butt.
All Jedi… Is that not a sufficient condition because they used “all”? All Jedi us the force so using the force is a sufficient condition of being a Jedi?
Only Jedi…is that not a necessary condition because they used “only”? While using the force is a necessary condition of being a Jedi it is not sufficient to guarantee membership in the Jedi order simply because one uses the force?
Only Arabic-speakers get PhDs. Chris is an Arabic speaker. Therefore Chris gets a PhD.
If gets a PhD, then an Arabic Speaker, written
PhD->Arabic-speaker
Now here's where you don't want to mess up. It says Chris is in that "Arabic-Speaker" portion, or in other words, he's someone in the necessary condition position. But we can't work backwards. We can't say if Chris (the necessary) speaks Arabic then he gets a PhD.
It's easier to see if we use three topics, as it builds on earlier lessons:
Would you say this can be simplified to: "If the sufficient condition is false, the necessary condition can be true or false", and "if the necessary condition is true, the sufficient condition can be true or false"?
I do not understand the second example. If the conditional indicator is Only, that translates to logic Uses Force --> Jedi. Since Dooku uses the force, he triggered the sufficient and is a Jedi. This is a valid logic. But why did the text say I made up my own premise? If the conditional indicator is only, I did not make anything up did I? it's very confusing.
If it says all jedi use the force, and count doku uses the force. Its reasonable to assume that hes a jedi based on the premises. Dont understand why thats not valid
#feedback Echoing what has been said, but videos would be really helpful. I don't understand what premise is being made up in the second half of these lessons.
Is it just me or does the x before A and B confuse anyone into thinking it's a negation.??... I know that negation is /A but x intuitively represents 'not' in my head agh!
I really don't like the examples used in 7Sage. Why do you always stick to the Jedi/force/Yoda whatever thing? For people who never watch the show or have absolutely zero interest in it, it's not helpful for studying at all
Why is the Lawgic shorthand for Jedi and Force all of the sudden A and B instead of J and F in these examples? It makes it impossible to match english to the Lawgic shorthand in order to follow along. What are we doing here? #feedback
11
Topics
PT Questions
Select Preptest
You've discovered a premium feature!
Subscribe to unlock everything that 7Sage has to offer.
Hold on there, stranger! You need a free account for that.
We love that you want to get going. Just create a free account below—it only takes a minute—and then you can continue!
Hold on there, stranger! You need a free account for that.
We love that you came here to read all the amazing posts from our 300,000+ members. They all have accounts too! Just create a free account below—it only takes a minute—and then you’re free to discuss anything!
Hold on there, stranger! You need a free account for that.
We love that you want to give us feedback! Just create a free account below—it only takes a minute—and then you’re free to vote on this!
Hold on there, you need to slow down.
We love that you want post in our discussion forum! Just come back in a bit to post again!
Subscribers can learn all the LSAT secrets.
Happens all the time: now that you've had a taste of the lessons, you just can't stop -- and you don't have to! Click the button.
128 comments
For those who have never seen Star Wars (me):
(1) All pilots can fly airplanes. Alex can fly airplanes. Therefore, Alex is a pilot.
This is invalid because someone could know how to fly planes and not be a pilot.
(2) Only pilots can fly airplanes. Alex can fly airplanes. Therefore, Alex is a pilot.
This is valid because anyone who can fly airplanes must be a pilot.
I understand this and the previous bc he used star wars again making the translation easier to dissect. Wording should be reworked on both but if you are confused on the language, he is saying the second example is an incorrect translation into lawgic, but because of that, it does make it a valid argument, however that is NOT what the statements are saying and you will pick a wrong answer.
I don't understand this same example used here again saying you made up your own premise. double confusion.
After reading these I think that the videos help me grasp it more.
I got home from reviewing demands and medical records to come and read! ughhh where are the videos!!
Failing a sufficient condition doesn't mean they cannot meet the necessary condition
Failing a necessary condition does mean that they cannot meet the sufficient condition
Meeting a sufficient condition does mean that they meet the necessary condition
Meeting a necessary condition does not mean that they meet the sufficient condition
I don't understand the last paragraph "The only problem is that you made up your own premise B -> A. The actual premise is A -> B. You confused sufficiency for necessity."
The rest of the lesson makes sense, but I'm totally lost when I read that. Maybe make a video or remove/clarify that paragraph? I don't see what that really adds here.
Valid conclusion: Only dogs play outside. Blanche plays outside. Therefore, Blanche is a dog.
Invalid conclusion: All dogs play outside. Blanche plays outside. Therefore, Blanche is a dog.
In the invalid conclusion, Blanche could be a part of another group since it does not explicitly state that you have to be a dog to play outside. She could be human, a cat, etc.
Ok so I also found this lesson confusing. What I think the key take away here is that just because the necessary condition is true tells us nothing about the sufficient condition. That's it.
My example:
All moms use the kitchen. I use the kitchen. Therefore, I am a mom
Lawgic:
Moms -> use kitchen
I KITCHEN
--
I MOM
This is Invalid. WHY? Because I'M NOT A MOM. I AM A SINGLE DUDE. Just because I am using the kitchen does that mean I am a mom? NO!
If you thought me using the kitchen meant I'm a mom you are confusing sufficiency for necessity. You are saying that using the kitchen is SUFFICENT for being a mom. you are saying "All those who use the kitchen are mom".
AFFIRMING THE NECESSARY CONDITION TELLS YOU NOTHING ABOUT THE SUFFICIENT CONDITION
All we know from the stimulus is that All moms use the kitchen.
Mom = Sufficient
Using kitchen = Necessary
If I affirm the necessary condition by saying "I use the kitchen" does that tell you anything about if I am a mom or not?
If the necessary condition is satisfied, it yields no information about the sufficient condition. The sufficient condition could be true or could be false.
Did I get it wrong?
"All" is from group 1-necessity conditional indicators, where what follows immediately after the indicator, in this case "all", is the necessary condition. So, lawgic would be:
All Jedi use the Force.
J -> F
Dooku use force:
D -> F
Dooku is Jedi:
D -> J. This conclusion is not valid from the given premise.
In case of "only", its from group 2-sufficiency conditional indicators. What follows immediately after the indicator, "only", is the sufficient condition. So, lawgic would be:
Only Jedi use the Force.
F -> J
Dooku uses the Force.
D -> F
Chaining conditionals:
D -> F -> J
D -> J
We can infer from the above that Dooku is Jedi, which is the conclusion in the argument.
What has made this easier for me is realizing that all is not the same as only. All refers to everything of a certain group. Only is more strict about the rules.
All dogs drink water. Other animals can drink water too.
ONLY dogs drink water. No other animals drink water.
I am also confused by this but I am a little new to studying for this oldest trick in the book that keeps kicking my butt.
All Jedi… Is that not a sufficient condition because they used “all”? All Jedi us the force so using the force is a sufficient condition of being a Jedi?
Only Jedi…is that not a necessary condition because they used “only”? While using the force is a necessary condition of being a Jedi it is not sufficient to guarantee membership in the Jedi order simply because one uses the force?
how is this any different than confusing sufficiency for necessity? I guess I don't understand why this is separate
#feedback
That last paragraph keeps tripping me up. A video would prob explain this better to avoid confusion.
SO in form it would be
A-->B
B
-------
nothing - we cannot conclude anything about A
I know this is simple but I want to make sure I am not missing it.
... did you ever hear the tragedy of Darth Plagueis the Wise?
Keep it simple: Think about this:
Only Arabic-speakers get PhDs. Chris is an Arabic speaker. Therefore Chris gets a PhD.
If gets a PhD, then an Arabic Speaker, written
PhD->Arabic-speaker
Now here's where you don't want to mess up. It says Chris is in that "Arabic-Speaker" portion, or in other words, he's someone in the necessary condition position. But we can't work backwards. We can't say if Chris (the necessary) speaks Arabic then he gets a PhD.
It's easier to see if we use three topics, as it builds on earlier lessons:
A->B->C
We can't say "if C, then B"
Would you say this can be simplified to: "If the sufficient condition is false, the necessary condition can be true or false", and "if the necessary condition is true, the sufficient condition can be true or false"?
I do not understand the second example. If the conditional indicator is Only, that translates to logic Uses Force --> Jedi. Since Dooku uses the force, he triggered the sufficient and is a Jedi. This is a valid logic. But why did the text say I made up my own premise? If the conditional indicator is only, I did not make anything up did I? it's very confusing.
If it says all jedi use the force, and count doku uses the force. Its reasonable to assume that hes a jedi based on the premises. Dont understand why thats not valid
#feedback Echoing what has been said, but videos would be really helpful. I don't understand what premise is being made up in the second half of these lessons.
Is it just me or does the x before A and B confuse anyone into thinking it's a negation.??... I know that negation is /A but x intuitively represents 'not' in my head agh!
Pretty please bring back videos.... #Feedback
I really don't like the examples used in 7Sage. Why do you always stick to the Jedi/force/Yoda whatever thing? For people who never watch the show or have absolutely zero interest in it, it's not helpful for studying at all
Why is the Lawgic shorthand for Jedi and Force all of the sudden A and B instead of J and F in these examples? It makes it impossible to match english to the Lawgic shorthand in order to follow along. What are we doing here? #feedback