LSAT Short Arguments - Practice Differences of Assumption Sufficient vs Assumption Necessary Flashcards
Assumption Sufficient (is AC enough for C? Look for stronger AC language than C) vs Necessary (is AC needed for C? Look for weaker AC language than C)
Conclusion: This dog might have eaten too much this morning.
AC: All dogs ate too much this morning.
Sufficient or Necessary?
Sufficient, Not Necessary
“All” covers “this”
“ate” covers “might have eaten”
“too much” = “too much”
“this morning” = this morning
Conclusion: This dog might have eaten too much this morning.
AC: Several dogs eat too much from time to time.
Sufficient or Necessary?
Neither
“Several” doesn’t necessarily cover “this”
“eat too much” = “ate too much”
“from time to time” = “this morning”
Conclusion: This dog might have eaten too much this morning.
AC: It is possible for a dog to eat too much.
Sufficient or Necessary?
Necessary, Not Sufficient
“a dog” (1 dog, somewhere, not all dogs) doesn’t necessarily cover “this dog”
“a dog”(1 dog, somewhere, not all dogs) is needed to know about “this dog”
“it is possible” is needed to know about “might”
“eat too much” = “eaten too much”
implicit “at some time” is needed to know about “this morning”
Negation test kill argument? “It is NOT possible for a dog to eat too much” kills the conclusion, so NEC
Conclusion: This dog might have eaten too much this morning.
AC: This dog probably ate too much this morning.
Sufficient or Necessary?
Sufficient, Not Necessary
“This dog” = “This dog”
“probably” covers “might” - but AC language not weaker than Conclusion
“ate too much” = “eaten too much”
“this morning” = “this morning”
Conclusion: This dog might have eaten too much this morning.
AC: This dog ate too much this morning.
Sufficient or Necessary?
Sufficient, Not Necessary
“This dog” = “This dog”
“ate” covers “might have eaten” but AC language not weaker than Conclusion
“too much” = “too much”
“this morning” = “this morning”
Conclusion: This dog might have eaten too much this morning.
AC: Every dog alive ate too much this morning.
Sufficient or Necessary?
Sufficient, Not Necessary
“Every dog alive” covers “this dog” but AC language not weaker than Conclusion
“ate” covers “might have eaten”
“too much” = “too much”
“this morning” = “this morning”
Conclusion: My mother will probably come to town to visit me this year.
AC: Most mothers visit their children at least once per year.
Sufficient or Necessary?
Not Sufficient, Not Necessary
“Most mothers” doesn’t necessarily cover “my mother”
“visit at least once per year” covers “probably visit me this year”
“Most mothers” in AC is not needed for “My mother”
“visit at least once per year” in AC is needed for “probably visit me this year”
Conclusion: My mother will probably come to town to visit me this year.
AC: All mothers visit their children at least twice per year.
Sufficient or Necessary?
Sufficient, Not Necessary
“All mothers” covers “My mother”
“All mothers” not needed to know “My mother”
“visit their children” covers “probably…visit me”
“twice per year” covers “this year”
Conclusion: My mother will probably come to town to visit me this year.
AC: My mother likes me.
Sufficient or Necessary?
Not Sufficient, Not Necessary
“My mother” covers “my mother”
“likes me” does not necessarily cover “probably…visit me”
Conclusion: My mother will probably come to town to visit me this year.
AC: There is a greater chance that my mother will visit me than there is that she will visit my brother.
Sufficient or Necessary?
Not Sufficient, Not Necessary
“my mother” covers “My mother”
“visit me” covers “visit me”
“greater chance…than…my brother” does not necessarily cover “probably…visit me”
“greater chance…than…my brother” is not needed to know “probably…visit me”
Conclusion: My mother will probably come to town to visit me this year.
AC: Mothers sometimes visit their children.
Sufficient or Necessary?
Not Sufficient, Necessary
“Mothers this means at least one mother generically, not necessarily all mothers)” does not cover “My mother”
“Mothers (at least one mother generically, not necessarily all)” is needed to know “My mother”
“sometimes visit their children (at SOME POINT in time, implicitly)” is needed to know “probably…visit me this year”
Negation Test (note that the negation of sometimes is never” Mothers never visit their children…yes that kills the argument, so it is NECESSARY
Conclusion: My mother will probably come to town to visit me this year.
AC: My mother will probably not commit a heinous crime that will put her in jail for the rest of the year before having a chance to visit me.
Sufficient or Necessary?
Not Sufficient, Necessary
“My mother” = “My mother”
“will probably (51%) NOT commit heinous crime TWPHIJFT rest of the year before having a chance to visit me” does not cover “probably…visit me” Not Sufficient
Is “will probably (51%) NOT commit heinous crime TWPHIJFT rest of the year before having a chance to visit me” needed for “probably…visit me”?
Try negation: “will probably (51%) commit heinous crime TWPHIJFT rest of the year before having a chance to visit me” will indeed kill the original argument (my mother will probably come to town to visit me this year) so AC is necessary
when you see a new term in the AC of Assumption Necessary (jail, disease), it might be relevant so don’t blow it off, check it with Negation Test
Conclusion: My mother will probably come to town to visit me this year.
AC: Everyone in the history of the universe is likely to visit me this year.
Sufficient or Necessary?
Sufficient, Not Necessary
“Everyone in HOU” covers “My mother”
“likely to visit me” covers “probably…visit me”
“this year” covers “this year” SUFFICIENT
“Everyone in HOU” needed to know for “My mother”? No
Conclusion: All people who suffer from swollen livers and spleens resulting from consumption of E-coli will die soon.
AC: All people who suffer from swollen livers and spleens could die soon.
Sufficient or Necessary?
Not Sufficient, Not Necessary
“All people who suffer from swollen livers and spleens” covers “APWSFSLAS resulting from the consumption of E coli”
“could die soon” does not necessarily cover “will die soon” Not Sufficient
Is “All people who suffer from swollen livers and spleens” needed to know about “APWSFSLAS resulting from the consumption of E coli”? No. Not Necessary.
Conclusion: All people who suffer from swollen livers and spleens resulting from consumption of E-coli will die soon.
AC: Some people who suffer from swollen livers and spleens could die soon.
Sufficient or Necessary?
Not Sufficient, Necessary
“Some people who suffer from swollen livers and spleens” does not necessarily cover “APWSFSLAS resulting from the consumption of E coli”
“could die soon” does not necessarily cover “will die soon” Not Sufficient
Is “Some people who suffer from swollen livers and spleens” needed to know “APWSFSLAS resulting from the consumption of E coli” Yes
Is “could die soon” needed to know “will die soon”? Yes Necessary
