I it's Mike again. I wanted to make another quick video
this time about five seemingly simple
words and phrases that cause test takers to lose thousands of points on the LSAT
every year most some
only if unless and
or the reason why these words are so dangerous
is that in real life whether we realize it or not their meaning changes slightly
based on the situation however on the LSAT
just as in formal logic these words have an absolute meaning
and of course it's important for you to understand them exactly the same way
as the test writers do. So let's quickly discuss.
Okay let's use a restaurant setting
to to discuss these terms and let's imagine that
you are this bulldog and and you ask the waiter how's the kale salad
and the waiter, who happens to be a bunny says
the kale salad is excellent. I think most of our customers would say
that it's their favorite dish. The implied meaning of the word most
in this context is that it is simply some
unknown amount that's greater than half now let's imagine instead that you asked
the waiter
do people like the kale salad and he replies
well most do the implied meaning
here of the word most is it's still greater than half
and but it's not all right there's a sense that that there are some
people
who don't like the the kale salad. so most has to slightly different meanings based
on
the situation right in one context it simply means more than half
and in the other there's an implication that it's more than half but not all
what does most mean when it appears on the LSAT? it takes on the more general
meaning
it simply means more than half most does not exclude
the possibility of all. Now that doesn't mean that the test writers
are going to try to trick you and use the term most when they should be using the term
all
but it does come into play when you think about inferences so when
you hear something like
well most customers like the kale salad
it would be wrong for you to falsely infer
that that must mean some people don't like the kale salad.
now let's move on to some and imagine the waiter says to you
some of our dishes are great for vegetarians the implied meaning here of the word
some is that it simply some sort of
unknown amount now it's imagine again that you asked that the waiter do
do people like the kale salad and I realize I probably shouldn't have used the term
people in these examples with
the ball dog and the bunny but let's just imagine the response well
well some people do; the implied meaning there of the word some is
that it's still an unknown amount
but it's an unknown minority right you get the sense that most people
do not like kale salad. so again
two slightly different meanings for the word some; in one context
it's a more general meaning simply means an unknown amount
and in the other it's a little bit more specific
it's an unknown amount that a minority what does some mean when
it appears on the LSAT? again just like most it takes on a more general
meaning some simply means
and unknown amount that has to be greater than 0
when you hear some it means it does exist but it could be anywhere
from slightly bigger than zero all the way up to a hundred percent
now let's move on to the phrase only if
imagine the waiter says to you you can get the happy our price
only if you order before six; the implication there
is if you order before six you're going to get the happy our price.
now it's imagine again you asked the waiter
Do people order the kale salad?
And the waiter responds they do order it but
only if they are vegetarians right the implication there
is if someone orders the kale salad that person
must be a vegetarian
the difference in meaning here is a little bit tougher to see so let's go ahead and
draw this out
in the first situation
notice that they're essentially what this at the implied meaning is
is that if we have the thing after the only if
you order before six then you're guaranteed the thing before the only if
right; you get that happy hour price notice in the second situation
whatthat only if guarantees is
if the thing before it happens right if you order the kale salad
then that's really a guarantee of everything after the only if you must be
a vegetarian
the implied meaning of that second phrase is not
that all vegetarians ordered the kale salad
so notice that in these two contexts
you could argue that only if actually means
the exact opposite thing relative to the situation.
So what does only if mean when you see it on the LSAT
on the LSAT it matches the meaning of the second situation
so when you see the term only if
what that tells you is that the thing before it guarantees the thing after it
okay so if they order the kale salad you know for sure they're vegetarians
you cannot say that if they're vegetarians
they for sure ordered the kale salad. Now let's move on to
unless and we'll use the two same situations that we use for only if
Imagine that the waiter says to you you can't get the happy our price
unless you order before six
the implied meaning there is if you order before six
you are guaranteed the happy our price
now let's imagine again that you ask the waiter do people order the kale salad?
and he says people don't order it unless they're vegetarians
implied meaning there is again that if you order the kale salad
you must be a vegetarian
so just like only if notice that
in these two situations we're using the term unless
in arguably opposite ways. In the first context,
You can't get the happy hour price unless you order before six,
the implied meaning there that you order before six you get the happy hour price:
in the second one people don't order the kale salad unless they're vegetarians
the implied meaning is not oh if they are vegetarians
they'll get the kale salad right it's that if they can't get the kale salad
they must be vegetarians what does unless mean
on the LSAT? Once again it matches the second of these phrases
so you see a phrase like
they don't order the kale salad unless they are vegetarians,
this means if they did order the kale salad they must've been vegetarians
it does not mean if they're vegetarians they must order the kale salad.
finally let's go ahead and talk about the word or -- let's imagine that the waiter says
to you
in-order to dine here you must be over 18
or accompanied by an adult
the implication here is that both is fine if you're over 18
and accompanied by an adult you can still dine there
now let's imagine the waiter asks would you like Soup or Salad
the implication here at is that both
is probably not OK
so in one context the implied meaning of or allows for the possibility of both
but in the other context it does not
what does or mean when it appears on the LSAT?
Unless otherwise stated the
or is inclusive meaning that both
is just fine okay so
most means more than half some is simply an unknown amount greater than 0
a only if b means that a guarantees b
not a unless b also means that a
guarantees b and or unless otherwise stated
is inclusive if you'd like to get more practice utilizing these terms
please check out my website the lsat trainer.com
in particular please take a look at the sufficient assumptions chapter
and the LSAT vocab chapter both of which are available for free
that's it I hope you found it helpful and I wish you the best on
the exam.