"I don't have this one, so I certainly won't get that one." "this one" is Necessary.
"I have this one, and it is it enough (but not for sure the only thing needed) to get that one." "this one" is Sufficient.
I cannot guarantee this will work every time, but it has worked every time so far for me.
I find the two main concepts in the sentence and I ask:
Necessary Question: "Is this one necessary to have that one?" or if the words necessary and sufficient are losing their meaning because we've heard them so much by now: "Will I certainly not get that one if I don't have this one?" If yes, "this one" is your Necessary idea and it goes on the right side of the arrow. Try both concepts for "this one".
Sufficient Question: "Is this one sufficient to have the other?" or "Is this one enough, but not for sure all that is needed, to allow for the other?" If yes, "this one" is your Sufficient idea and it goes on the left side of the arrow. Try both concepts for "this one".
Necessary example:
"Hitting a nail requires a hammer"
Necessary Question: "Is hitting a nail necessary to a hammer?" or "Will I certainly not a hammer if I don't hitting a nail?" No. Switch concepts. "Is a hammer necessary to hitting a nail?" or "Will I certainly not hit the nail if I don't have a hammer?." Yes!
"Hammer" is necessary. Goes on the right
hit a nail -> hammer
Sufficient Example:
"Politicians that love the environment support policies to grow trees."
Necessary Question: "Are politicians that love the environment necessary to support policies to grow trees?" or "Will I certainly not get policies to grow trees if I don't have politicians that love the environment?" NO. Logically we may think so, but it's not necessary (always required).
Sufficient Question: "Is being a politician that loves the environment sufficient to support policies that grow trees?" or "Are politicians that love the environment enough, but not for sure all that is needed to support politics to grow trees." Yes.
"Politicians that love the environment" is sufficient. Goes on the left
politicians that love the environment -> policies to grow trees
@NathanielWright I do the same thing and it helps a lot! It's like when we learned about hypotheses in elementary school (at least where we did). They always had to be if...then statements, and this logic makes some sense to apply to LR!
I saw a video that explained the relationship as Sufficient (Trigger) and Necessary (What must/will happen when the trigger is met). This helped me grasp the concept easily.
I was struggling with this for a while but I think it finally clicked so I am leaving this here.
take the contrapositive if you are unsure. for example
-> The students who mastered logic saw improvements in their PrepTest scores.
my initial thought the first time was Improvements -> mastering test scores and I obviously got it wrong, so I looked up some examples on YouTube that helped
think of a red object if I were to write in lawgic:
color -> red, which would read as color is sufficient for red, now if I take the contrapositive /red->/color this idea can't be right, because if there's no red there is no color doesn't makes sense. it could be blue, orange, yellow, etc. now we do the opposite: red -> color, red is sufficient for color, take the contra positive: /color -> /red, if no color then it can't be red, now this makes more sense, right, because it's either there is color or not, there can be no substitutes.
now applying this to the example:
I took improvements -> mastering test scores took the contrapositive /mastering logic -> /improve, but this can't be true, because mastering logic can be substituted what if their test scores improved because of a tutor, maybe the teacher handed out extra credit, maybe covid 2027 came out and they could use chatgpt to answer everything idk all I know is that its not plausible to say just because this one thing did not happen does that mean that you did not improve.
now for the right answer:
mastering logic -> improvements
/improvements -> /mastering logic applying that same logic that I did for the wrong answer with the substitution could improvements have a substitute either than if they did or not? no of course not stagnant? not improved. decreased? not improve its either or, which means that improvements are required on mastering logic, but mastering logic isnt the ONLY thing to improve test score.
being a color is REQUIRED for a red object, but being a red object isnt the ONLY color for the object to be. I hope this helps someone!
I've reached a point in studying where I feel like I'll never understand any of this. Does it get any better guys!? I'm planning on taking the october lsat and I don't know where to start.
@AlvinB Exactly! that's what's been on my mind throughout these lessons. I'm glad that someone else is seeing that too.
We wouldn't have time in the exam to do all this logical analysis, so we need to find which clause sounds like an absolute fact statement (conclusion) and which clause supports that clause (premise). For example,
It will not rain unless Zeus is mad.
=If not Zeus is mad, it will not rain.
=If it rains, then Zuest must be mad.
/Z->/R
R->Z
It is being claimed that for it to rain something specific/absolute happens, which is, Zeus needs to be mad i.e. it is required that Zeus is mad.
When you put it through the "why, because" test for premise-conclusion, you'll see that:
Zeus must be mad, why?-> Conclusion(receiving support)/Necessary
Because it will rain.->Premise (throwing support)/Sufficient
This is actually a great method for assigning symbols when translating. When I translate into Lawgic one of my biggest obstacles is figuring out which symbols to assign to which. But with this method is actually made easier because I just assign the symbols based on the subject of the sentence and the object.
Like in the example: The kingdoms in Westeros whose economies rely predominantly on trade support foreign policies that aim to secure peace.
The kernel of the sentence is simply "Kingdoms support policies". Everything else is just modifiers.
So when looking at it like this I just assign the symbols as "K" for kingdoms and "P" for policies.
So the translation to Lawgic looks like this: K → P
Not always helpful when the modifiers are the distinction! For example, you wouldn't want to use K if the next sentence was "Kingdoms in Westeros whose economies rely predominantly on agriculture support foreign policies that aim to support neutrality". Or if the next sentence was "Kingdoms in Middle Earth whose economies rely predominantly on trade support foreign policies that aim for strong defense systems". I always read the full stimulus before picking my symbol so I avoid picking one that's confusing or could be too similar to another one.
Trying to gain a deeper understanding of conditional logic without relying on words, so from my understanding "An engaging plot will guarantee a novel's commercial success" does NOT mean that if the novel has commercial success it has an engaging plot.
That would be an example of mistaking sufficiency for necessity.
I think its less about memorizing what necessarily comes AFTER the conditional word, but having a good grasp of referential phrasing to understand what the conditional indicator is for, regardless of order.
Can there be overall indicators for knowing when there is a conditional relationship-- like in general, necessary conditions are restrictive/obligatory parts of the relationship, whereas sufficient conditions are more of objects or things that belong to different categories. I don't know if this makes much sense, but just some pointer that is easier to recognize...
This just confused me. The explanation for why its necessary is just its necessary and the explanation for sufficient is just its sufficient. That did not help me at all.
is it safe to say that a good over and under inclusive rule is that when the verb is active the subject is sufficent and when the verb is passive the predicate is sufficient?
155 comments
Here's what I'm doing that works.
TLDR: Find the two concepts and compare.
"I don't have this one, so I certainly won't get that one." "this one" is Necessary.
"I have this one, and it is it enough (but not for sure the only thing needed) to get that one." "this one" is Sufficient.
I cannot guarantee this will work every time, but it has worked every time so far for me.
I find the two main concepts in the sentence and I ask:
Necessary Question: "Is this one necessary to have that one?" or if the words necessary and sufficient are losing their meaning because we've heard them so much by now: "Will I certainly not get that one if I don't have this one?" If yes, "this one" is your Necessary idea and it goes on the right side of the arrow. Try both concepts for "this one".
Sufficient Question: "Is this one sufficient to have the other?" or "Is this one enough, but not for sure all that is needed, to allow for the other?" If yes, "this one" is your Sufficient idea and it goes on the left side of the arrow. Try both concepts for "this one".
Necessary example:
"Hitting a nail requires a hammer"
Necessary Question: "Is hitting a nail necessary to a hammer?" or "Will I certainly not a hammer if I don't hitting a nail?" No. Switch concepts. "Is a hammer necessary to hitting a nail?" or "Will I certainly not hit the nail if I don't have a hammer?." Yes!
"Hammer" is necessary. Goes on the right
hit a nail -> hammer
Sufficient Example:
"Politicians that love the environment support policies to grow trees."
Necessary Question: "Are politicians that love the environment necessary to support policies to grow trees?" or "Will I certainly not get policies to grow trees if I don't have politicians that love the environment?" NO. Logically we may think so, but it's not necessary (always required).
Sufficient Question: "Is being a politician that loves the environment sufficient to support policies that grow trees?" or "Are politicians that love the environment enough, but not for sure all that is needed to support politics to grow trees." Yes.
"Politicians that love the environment" is sufficient. Goes on the left
politicians that love the environment -> policies to grow trees
Manifesting 180
@Dsamuel5 locked in.
What's really helped me is forcing "if, then" to fit in the sentence. Not sure if this is a bad habit or not, but for example:
"The students who mastered logic saw improvements in their PrepTest scores."
What I did for this was intuitively divide up the sentence into the subject and predicate, then fit "If" and "Then" before them, resulting in:
"if you are a student who mastered logic, then you saw improvements to your PrepTest score"
It's really a backwards way of doing essentially the same thing described in this video, but I've found it to be much more intuitive for myself
@NathanielWright I do the same thing and it helps a lot! It's like when we learned about hypotheses in elementary school (at least where we did). They always had to be if...then statements, and this logic makes some sense to apply to LR!
I am definitely getting confused in more complicated sufficient and necessary conditions.
Hopefully more practice equals more accuracy.
Hmmmm. Yeah, no. I'm taking my Webster's dictionary to the LSAT as part as my accomodation.
The subject -> predicate was a lightbulb moment. Thank you for explaining it that way!
@CheyenneBandy So does JY mean it is always Subject ---> Predicate? If so this is really cool. Also a lightbulb moment for me
I saw a video that explained the relationship as Sufficient (Trigger) and Necessary (What must/will happen when the trigger is met). This helped me grasp the concept easily.
Can you link to this video, please?
@Temi_123 Antecedent -> Consequent
This is tough, but we're gonna get through it guys!
''True mastery REQUIRES understanding the concepts of sufficiency and necessity.''
Well played 7Sage... well played.
lmao. mastery → understanding concepts.
I have been having trouble grasping this concept, but this video has helped me tremendously.
@mibuch commenting for reference
@mibuch commenting for reference
I was struggling with this for a while but I think it finally clicked so I am leaving this here.
take the contrapositive if you are unsure. for example
-> The students who mastered logic saw improvements in their PrepTest scores.
my initial thought the first time was Improvements -> mastering test scores and I obviously got it wrong, so I looked up some examples on YouTube that helped
think of a red object if I were to write in lawgic:
color -> red, which would read as color is sufficient for red, now if I take the contrapositive /red->/color this idea can't be right, because if there's no red there is no color doesn't makes sense. it could be blue, orange, yellow, etc. now we do the opposite: red -> color, red is sufficient for color, take the contra positive: /color -> /red, if no color then it can't be red, now this makes more sense, right, because it's either there is color or not, there can be no substitutes.
now applying this to the example:
I took improvements -> mastering test scores took the contrapositive /mastering logic -> /improve, but this can't be true, because mastering logic can be substituted what if their test scores improved because of a tutor, maybe the teacher handed out extra credit, maybe covid 2027 came out and they could use chatgpt to answer everything idk all I know is that its not plausible to say just because this one thing did not happen does that mean that you did not improve.
now for the right answer:
mastering logic -> improvements
/improvements -> /mastering logic applying that same logic that I did for the wrong answer with the substitution could improvements have a substitute either than if they did or not? no of course not stagnant? not improved. decreased? not improve its either or, which means that improvements are required on mastering logic, but mastering logic isnt the ONLY thing to improve test score.
being a color is REQUIRED for a red object, but being a red object isnt the ONLY color for the object to be. I hope this helps someone!
Excellent last few slides. a lot of subtle BUT very big things happening that i am now seeing more clearly!
Conditional and set logic is a lot of, "What comes first, the chicken or the egg?"
I've reached a point in studying where I feel like I'll never understand any of this. Does it get any better guys!? I'm planning on taking the october lsat and I don't know where to start.
@ShinyLoser It gets better.
I thought the "Let's Review" part of the video was another example so I started finding the subject predicate of it 😂😭
Would you say a good idea is that the sufficient clause is the main point that is "doing" the work? While necessary receives the work?
@AlvinB Exactly! that's what's been on my mind throughout these lessons. I'm glad that someone else is seeing that too.
We wouldn't have time in the exam to do all this logical analysis, so we need to find which clause sounds like an absolute fact statement (conclusion) and which clause supports that clause (premise). For example,
It will not rain unless Zeus is mad.
=If not Zeus is mad, it will not rain.
=If it rains, then Zuest must be mad.
/Z->/R
R->Z
It is being claimed that for it to rain something specific/absolute happens, which is, Zeus needs to be mad i.e. it is required that Zeus is mad.
When you put it through the "why, because" test for premise-conclusion, you'll see that:
Zeus must be mad, why?-> Conclusion(receiving support)/Necessary
Because it will rain.->Premise (throwing support)/Sufficient
This is actually a great method for assigning symbols when translating. When I translate into Lawgic one of my biggest obstacles is figuring out which symbols to assign to which. But with this method is actually made easier because I just assign the symbols based on the subject of the sentence and the object.
Like in the example: The kingdoms in Westeros whose economies rely predominantly on trade support foreign policies that aim to secure peace.
The kernel of the sentence is simply "Kingdoms support policies". Everything else is just modifiers.
So when looking at it like this I just assign the symbols as "K" for kingdoms and "P" for policies.
So the translation to Lawgic looks like this: K → P
Not always helpful when the modifiers are the distinction! For example, you wouldn't want to use K if the next sentence was "Kingdoms in Westeros whose economies rely predominantly on agriculture support foreign policies that aim to support neutrality". Or if the next sentence was "Kingdoms in Middle Earth whose economies rely predominantly on trade support foreign policies that aim for strong defense systems". I always read the full stimulus before picking my symbol so I avoid picking one that's confusing or could be too similar to another one.
Trying to gain a deeper understanding of conditional logic without relying on words, so from my understanding "An engaging plot will guarantee a novel's commercial success" does NOT mean that if the novel has commercial success it has an engaging plot.
That would be an example of mistaking sufficiency for necessity.
Correct it could have been a success due to other reasons such as popularity of the author etc.
brain mush
I think its less about memorizing what necessarily comes AFTER the conditional word, but having a good grasp of referential phrasing to understand what the conditional indicator is for, regardless of order.
It helps me to think back to the NYC -> USA example.
For guarantee:
Being in nyc GUARANTEES being in the usa.
Being in the usa is GUARANTEED by being in nyc.
For require:
Being in nyc REQUIRES being in the usa.
Being in the usa is REQUIRED to be in nyc.
Can there be overall indicators for knowing when there is a conditional relationship-- like in general, necessary conditions are restrictive/obligatory parts of the relationship, whereas sufficient conditions are more of objects or things that belong to different categories. I don't know if this makes much sense, but just some pointer that is easier to recognize...
This just confused me. The explanation for why its necessary is just its necessary and the explanation for sufficient is just its sufficient. That did not help me at all.
is it safe to say that a good over and under inclusive rule is that when the verb is active the subject is sufficent and when the verb is passive the predicate is sufficient?