How to figure out Sufficient & Necessary without usual indicators?

Comments

• 1 Like

  WinningHere Member

  February 2021 417 karma

  Try to translate into an "if -------> then" statement?
• 1 Like

  CardsnHogz Alum Member

  February 2021 168 karma

  I tricked my head back and forth when I first started. Then I woke up and quit making it so dang complicated!

  What does the word necessary mean to you? To me it's...well necessary. It's required. I HAVE TO HAVE IT. These are all synonyms for necessary.

  Your example is a bit further off the ledge (b/c it's the actual LSAT) but it says like "something demands the memorization of unfamiliar commands". Demand is the necessary condition indicator. It's used just like "requires". "Something requires the memorization of unfamiliar commands"

  Whatever it is that you MUST have, are required to have, or whatever is necessary, that's your necessary condition.

  The "thing" that is DOING the "requiring", that's your sufficient condition.

  The sufficient can't exist without it's requirements. So when you see the sufficient existing, you know it has it's requirements. It has it's necessary conditions fulfilled.
• lsat2021-1 Core Member

  February 2021 246 karma

  @CardsnHogz said:
  I tricked my head back and forth when I first started. Then I woke up and quit making it so dang complicated!

  What does the word necessary mean to you? To me it's...well necessary. It's required. I HAVE TO HAVE IT. These are all synonyms for necessary.

  Your example is a bit further off the ledge (b/c it's the actual LSAT) but it says like "something demands the memorization of unfamiliar commands". Demand is the necessary condition indicator. It's used just like "requires". "Something requires the memorization of unfamiliar commands"

  Whatever it is that you MUST have, are required to have, or whatever is necessary, that's your necessary condition.

  The "thing" that is DOING the "requiring", that's your sufficient condition.

  The sufficient can't exist without it's requirements. So when you see the sufficient existing, you know it has it's requirements. It has it's necessary conditions fulfilled.

  Hi thanks for your reply! I think I should have mentioned the full sentence to make it more clear. Here the sentence in PT26.S3.Q21 that confuses me is that "we that it is expensive to teach people a software that demands requires the memorization of unfamiliar commands" JY diagrams this sentence as DMUS ---> E

  I understand that requires is usually a Necessary indicator but here the bit after the indicator is falling into the sufficient which is confusing me.
• 1 Like

  SweetyC137 Member

  February 2021 edited February 2021 80 karma

  DMUS = demands memorization of unfamiliar commands - I think me may meant to have written a "C" but wrote an "S" because was thinking about software. But this is just a guess on my part.

  E = Expensive

  When something is in the necessary condition, it means that, in the world of software that demand memorization of unfamiliar commands, we KNOW that it is expensive. Other things in this world can also be expensive, but we know for sure that things that DMUS, are expensive, according to this statement.

  Think of it this way, Ellen Cassidy, the author of The Loophole, talks about using "The What Test." Add a "what" to whichever side of the indicator makes grammatical sense. What is the indicator referring to? (Examples: If what?, when what?, people who what? In order to what?, What's essential?)

  So, for your specific sentence that you had mentioned....Things that demand memorization of unfamiliar commands are what? They are expensive.

  "Sufficient indicators are inclusive, open words. Whereas necessary indicators come from a place of certainty. They are ironclad, serious and restrictive. They are obligations. What's important isn't how the conditionals are expressed, but the core relationship hiding underneath the language." - Paraphrasing from The Loophole
• 1 Like

  lsat2021-1 Core Member

  February 2021 246 karma

  @SweetyC137 said:
  DMUS = demands memorization of unfamiliar commands - I think me may meant to have written a "C" but wrote an "S" because was thinking about software. But this is just a guess on my part.

  E = Expensive

  When something is in the necessary condition, it means that, in the world of software that demand memorization of unfamiliar commands, we KNOW that it is expensive. Other things in this world can also be expensive, but we know for sure that things that DMUS, are expensive, according to this statement.

  Think of it this way, Ellen Cassidy, the author of The Loophole, talks about using "The What Test." Add a "what" to whichever side of the indicator makes grammatical sense. What is the indicator referring to? (Examples: If what?, when what?, people who what? In order to what?, What's essential?)

  So, for your specific sentence that you had mentioned....Things that demand memorization of unfamiliar commands are what? They are expensive.

  "Sufficient indicators are inclusive, open words. Whereas necessary indicators come from a place of certainty. They are ironclad, serious and restrictive. They are obligations. What's important isn't how the conditionals are expressed, but the core relationship hiding underneath the language." - Paraphrasing from The Loophole

  Ah I see! Thank you so much!
• 1 Like

  KevinLuminateLSAT Alum Member

  February 2021 984 karma

  OP, I think there are two issues that may be causing difficulty for you.

  Sentences are made up of a subject and a predicate (which is basically the thing that the subject does or the fact that we are getting about the subject). Generally, unless the predicate is about something being necessary/sufficient, you can think of the subject as the sufficient condition and the predicate as the necessary condition.

  Take this example: "Alligators are not good pets." Here, the subject is alligators and the fact we are getting about them is that they are not good pets. So you can think of this as "If alligator -> Not good pet."

  Contrast that with this: "A science degree is necessary to be hired at the NIH." Here, even though science degree is the grammatical subject of the sentence, and "being necessary to be hired at the NIH" is the predicate, because the predicate is saying that the science degree is necessary, the way to think about this sentence is "If hired at NIH -> Science degree". (This shows how when the predicate is labeling the subject of the sentence as sufficient/necessary, you don't want to blindly follow the general rule I described above about the subject = sufficient and predicate = necessary.)

  Now I'll note the two tricky things that arise in the example sentence you're asking about.

  First, in a more complicated sentence, the subject may include a modifier that has conditional language. But that modifier doesn't change anything about how we understand the relationship between the subject and the predicate. The subject is still going to be the sufficient and the predicate is still going to be the necessary.

  For example: "Animals that require multiple daily walks to be happy are tough to care for."

  The subject of this sentence (the thing the sentence is giving me a fact about) is "animals that require multiple daily walks to be happy". The predicate is "are tough to care for". So I would diagram this like so:

  If the animal requires multiple daily walks to be happy -> tough to care for it.

  The part saying "requires multiple daily walks to be happy" is not going to the necessary condition of the whole sentence because it's simply part of the modifier of "animals". What's the class of things that the sentence is about? Animals that require multiple daily walks to be happy. Treat that whole idea as the sufficient condition.

  (On the other hand, if the sentence were just "Animals require multiple daily walks to be happy", now this is saying that all animals need multiple daily walks to be happy, and the correct interpretation would be "If an animal is happy -> must have multiple daily walks.")

  The second tricky thing in the sentence you're asking about is that the subject of the sentence is not at the beginning. Take the same sentence we used before: "Animals that require multiple daily walks to be happy are tough to care for." Now let me reword the sentence without changing the meaning:

  "It is tough to care for animals that require multiple daily walks to be happy."

  It's still diagrammed as "Animals that require multiple daily walks -> tough to care for" because the thing that the sentence is giving me a fact about is still "animals that require multiple daily walks to be happy". That's still the subject. And the predicate is still "tough to care for" even though it appears in the first half of the sentence.

  All this is to say that English allows for awkward sentences and we have to careful about how we're parsing each sentence.

  So now to the sentence you're asking about:

  "It is expensive to teach people a software that requires the memorization of unfamiliar commands."

  The subject is "software that requires memorization of unfamiliar commands". The predicate is "expensive to teach". So "If software that requires memorization of unfamiliar commands -> then it is expensive to teach."
• lsat2021-1 Core Member

  February 2021 edited February 2021 246 karma

  @KevinLuminateLSAT said:
  OP, I think there are two issues that may be causing difficulty for you.

  Sentences are made up of a subject and a predicate (which is basically the thing that the subject does or the fact that we are getting about the subject). Generally, unless the predicate is about something being necessary/sufficient, you can think of the subject as the sufficient condition and the predicate as the necessary condition.

  Take this example: "Alligators are not good pets." Here, the subject is alligators and the fact we are getting about them is that they are not good pets. So you can think of this as "If alligator -> Not good pet."

  Contrast that with this: "A science degree is necessary to be hired at the NIH." Here, even though science degree is the grammatical subject of the sentence, and "being necessary to be hired at the NIH" is the predicate, because the predicate is saying that the science degree is necessary, the way to think about this sentence is "If hired at NIH -> Science degree". (This shows how when the predicate is labeling the subject of the sentence as sufficient/necessary, you don't want to blindly follow the general rule I described above about the subject = sufficient and predicate = necessary.)

  Now I'll note the two tricky things that arise in the example sentence you're asking about.

  First, in a more complicated sentence, the subject may include a modifier that has conditional language. But that modifier doesn't change anything about how we understand the relationship between the subject and the predicate. The subject is still going to be the sufficient and the predicate is still going to be the necessary.

  For example: "Animals that require multiple daily walks to be happy are tough to care for."

  The subject of this sentence (the thing the sentence is giving me a fact about) is "animals that require multiple daily walks to be happy". The predicate is "are tough to care for". So I would diagram this like so:

  If the animal requires multiple daily walks to be happy -> tough to care for it.

  The part saying "requires multiple daily walks to be happy" is not going to the necessary condition of the whole sentence because it's simply part of the modifier of "animals". What's the class of things that the sentence is about? Animals that require multiple daily walks to be happy. Treat that whole idea as the sufficient condition.

  (On the other hand, if the sentence were just "Animals require multiple daily walks to be happy", now this is saying that all animals need multiple daily walks to be happy, and the correct interpretation would be "If an animal is happy -> must have multiple daily walks.")

  The second tricky thing in the sentence you're asking about is that the subject of the sentence is not at the beginning. Take the same sentence we used before: "Animals that require multiple daily walks to be happy are tough to care for." Now let me reword the sentence without changing the meaning:

  "It is tough to care for animals that require multiple daily walks to be happy."

  It's still diagrammed as "Animals that require multiple daily walks -> tough to care for" because the thing that the sentence is giving me a fact about is still "animals that require multiple daily walks to be happy". That's still the subject. And the predicate is still "tough to care for" even though it appears in the first half of the sentence.

  All this is to say that English allows for awkward sentences and we have to careful about how we're parsing each sentence.

  So now to the sentence you're asking about:

  "It is expensive to teach people a software that requires the memorization of unfamiliar commands."

  The subject is "software that requires memorization of unfamiliar commands". The predicate is "expensive to teach". So "If software that requires memorization of unfamiliar commands -> then it is expensive to teach."

  Wow okay this is VERY helpful to keep in mind for the future. Thanks!!! Just so I don't make the same mistake again of blindly using this subject/predicate identification method like I did with the necessary and sufficient indicator words could you please give me an example of a sentence where the predicate is about something being necessary/sufficient?
• SufficientCondition Alum Member

  February 2021 311 karma

  One big moment for me was recognizing that the "arrow" has meanings in both directions, not just one. Yes, SC leads to NC, BUT SC "demands" (from your example) the NC. "Writing requires a pencil." is enough to conclude. W-->P.

  Let me know if that helps.
• 1 Like

  KevinLuminateLSAT Alum Member

  February 2021 984 karma

  @natal310 said:

  @KevinLuminateLSAT said:
  OP, I think there are two issues that may be causing difficulty for you.

  Sentences are made up of a subject and a predicate (which is basically the thing that the subject does or the fact that we are getting about the subject). Generally, unless the predicate is about something being necessary/sufficient, you can think of the subject as the sufficient condition and the predicate as the necessary condition.

  Take this example: "Alligators are not good pets." Here, the subject is alligators and the fact we are getting about them is that they are not good pets. So you can think of this as "If alligator -> Not good pet."

  Contrast that with this: "A science degree is necessary to be hired at the NIH." Here, even though science degree is the grammatical subject of the sentence, and "being necessary to be hired at the NIH" is the predicate, because the predicate is saying that the science degree is necessary, the way to think about this sentence is "If hired at NIH -> Science degree". (This shows how when the predicate is labeling the subject of the sentence as sufficient/necessary, you don't want to blindly follow the general rule I described above about the subject = sufficient and predicate = necessary.)

  Now I'll note the two tricky things that arise in the example sentence you're asking about.

  First, in a more complicated sentence, the subject may include a modifier that has conditional language. But that modifier doesn't change anything about how we understand the relationship between the subject and the predicate. The subject is still going to be the sufficient and the predicate is still going to be the necessary.

  For example: "Animals that require multiple daily walks to be happy are tough to care for."

  The subject of this sentence (the thing the sentence is giving me a fact about) is "animals that require multiple daily walks to be happy". The predicate is "are tough to care for". So I would diagram this like so:

  If the animal requires multiple daily walks to be happy -> tough to care for it.

  The part saying "requires multiple daily walks to be happy" is not going to the necessary condition of the whole sentence because it's simply part of the modifier of "animals". What's the class of things that the sentence is about? Animals that require multiple daily walks to be happy. Treat that whole idea as the sufficient condition.

  (On the other hand, if the sentence were just "Animals require multiple daily walks to be happy", now this is saying that all animals need multiple daily walks to be happy, and the correct interpretation would be "If an animal is happy -> must have multiple daily walks.")

  The second tricky thing in the sentence you're asking about is that the subject of the sentence is not at the beginning. Take the same sentence we used before: "Animals that require multiple daily walks to be happy are tough to care for." Now let me reword the sentence without changing the meaning:

  "It is tough to care for animals that require multiple daily walks to be happy."

  It's still diagrammed as "Animals that require multiple daily walks -> tough to care for" because the thing that the sentence is giving me a fact about is still "animals that require multiple daily walks to be happy". That's still the subject. And the predicate is still "tough to care for" even though it appears in the first half of the sentence.

  All this is to say that English allows for awkward sentences and we have to careful about how we're parsing each sentence.

  So now to the sentence you're asking about:

  "It is expensive to teach people a software that requires the memorization of unfamiliar commands."

  The subject is "software that requires memorization of unfamiliar commands". The predicate is "expensive to teach". So "If software that requires memorization of unfamiliar commands -> then it is expensive to teach."

  Wow okay this is VERY helpful to keep in mind for the future. Thanks!!! Just so I don't make the same mistake again of blindly using this subject/predicate identification method like I did with the necessary and sufficient indicator words could you please give me an example of a sentence where the predicate is about something being necessary/sufficient?

  Sure, that's this example here:

  Contrast that with this: "A science degree is necessary to be hired at the NIH." Here, even though science degree is the grammatical subject of the sentence, and "being necessary to be hired at the NIH" is the predicate, because the predicate is saying that the science degree is necessary, the way to think about this sentence is "If hired at NIH -> Science degree".

  Let me try another example. Contrast the following:

  "An A+ average is difficult to achieve."
  "An A+ average is required to be named valedictorian."

  The first sentence, if you want to think of it in terms of a conditional, is "If A+ average -> difficult to achieve." The subject is A+ average, and the fact we're getting about it is that it's difficult to get.

  The second sentence, however, is more usefully understood as "If named valedictorian -> A+ average." Even though "A+ average" is still the grammatical subject of the sentence, the predicate is saying that this subject is necessary for something else. So that's why A+ is now the necessary condition.
• 1 Like

  Glutton for the LSAT Alum Member ⭐

  February 2021 551 karma

  For necessary assumptions, one quick tip is to see what is mentioned in the premise that is NOT mentioned in the conclusion. That way, you determine the gap in reasoning.
• lsat2021-1 Core Member

  February 2021 246 karma

  @KevinLuminateLSAT said:

  @natal310 said:

  @KevinLuminateLSAT said:
  OP, I think there are two issues that may be causing difficulty for you.

  Sentences are made up of a subject and a predicate (which is basically the thing that the subject does or the fact that we are getting about the subject). Generally, unless the predicate is about something being necessary/sufficient, you can think of the subject as the sufficient condition and the predicate as the necessary condition.

  Take this example: "Alligators are not good pets." Here, the subject is alligators and the fact we are getting about them is that they are not good pets. So you can think of this as "If alligator -> Not good pet."

  Contrast that with this: "A science degree is necessary to be hired at the NIH." Here, even though science degree is the grammatical subject of the sentence, and "being necessary to be hired at the NIH" is the predicate, because the predicate is saying that the science degree is necessary, the way to think about this sentence is "If hired at NIH -> Science degree". (This shows how when the predicate is labeling the subject of the sentence as sufficient/necessary, you don't want to blindly follow the general rule I described above about the subject = sufficient and predicate = necessary.)

  Now I'll note the two tricky things that arise in the example sentence you're asking about.

  First, in a more complicated sentence, the subject may include a modifier that has conditional language. But that modifier doesn't change anything about how we understand the relationship between the subject and the predicate. The subject is still going to be the sufficient and the predicate is still going to be the necessary.

  For example: "Animals that require multiple daily walks to be happy are tough to care for."

  The subject of this sentence (the thing the sentence is giving me a fact about) is "animals that require multiple daily walks to be happy". The predicate is "are tough to care for". So I would diagram this like so:

  If the animal requires multiple daily walks to be happy -> tough to care for it.

  The part saying "requires multiple daily walks to be happy" is not going to the necessary condition of the whole sentence because it's simply part of the modifier of "animals". What's the class of things that the sentence is about? Animals that require multiple daily walks to be happy. Treat that whole idea as the sufficient condition.

  (On the other hand, if the sentence were just "Animals require multiple daily walks to be happy", now this is saying that all animals need multiple daily walks to be happy, and the correct interpretation would be "If an animal is happy -> must have multiple daily walks.")

  The second tricky thing in the sentence you're asking about is that the subject of the sentence is not at the beginning. Take the same sentence we used before: "Animals that require multiple daily walks to be happy are tough to care for." Now let me reword the sentence without changing the meaning:

  "It is tough to care for animals that require multiple daily walks to be happy."

  It's still diagrammed as "Animals that require multiple daily walks -> tough to care for" because the thing that the sentence is giving me a fact about is still "animals that require multiple daily walks to be happy". That's still the subject. And the predicate is still "tough to care for" even though it appears in the first half of the sentence.

  All this is to say that English allows for awkward sentences and we have to careful about how we're parsing each sentence.

  So now to the sentence you're asking about:

  "It is expensive to teach people a software that requires the memorization of unfamiliar commands."

  The subject is "software that requires memorization of unfamiliar commands". The predicate is "expensive to teach". So "If software that requires memorization of unfamiliar commands -> then it is expensive to teach."

  Wow okay this is VERY helpful to keep in mind for the future. Thanks!!! Just so I don't make the same mistake again of blindly using this subject/predicate identification method like I did with the necessary and sufficient indicator words could you please give me an example of a sentence where the predicate is about something being necessary/sufficient?

  Sure, that's this example here:

  Contrast that with this: "A science degree is necessary to be hired at the NIH." Here, even though science degree is the grammatical subject of the sentence, and "being necessary to be hired at the NIH" is the predicate, because the predicate is saying that the science degree is necessary, the way to think about this sentence is "If hired at NIH -> Science degree".

  Let me try another example. Contrast the following:

  "An A+ average is difficult to achieve."
  "An A+ average is required to be named valedictorian."

  The first sentence, if you want to think of it in terms of a conditional, is "If A+ average -> difficult to achieve." The subject is A+ average, and the fact we're getting about it is that it's difficult to get.

  The second sentence, however, is more usefully understood as "If named valedictorian -> A+ average." Even though "A+ average" is still the grammatical subject of the sentence, the predicate is saying that this subject is necessary for something else. So that's why A+ is now the necessary condition.

  Okay thanks for clarification!!!