Respectfully Snape was never a potions professor when Slughorn was a professor. Thus, because I am a big fat nerd, the first argument is factually invalid.
There might be ways to trick someone here that people might want to watch out for. Let's take the first example:
Most students in Prof. Snape's class can brew potions masterfully. All students who can masterfully brew potions are invited to join the Slug Club. Therefore, most students in Prof. Snape's class are invited to join the Slug Club.
This works, is valid. But, if we just remove the modifier to "in professor Snape's Class" we change the domain, superset/subset relationship. whatever. We get:
Most students in Prof. Snape's class can brew potions masterfully. All students who can masterfully brew potions are invited to join the Slug Club. Therefore, most students are invited to join the Slug Club.
We don't know which electric cars are red. The Teslas might all be among the minority that aren't red. It's possible, but not necessary — and logic only allows conclusions that are guaranteed by the premises.
To use numbers: say you have 1,000 Teslas. So you know you have 1,000 (at least) electric cars (from the first premise).
We don’t know how many electric cars exist in total, but clearly, it’s more than 1,000 (since not all electric cars are Teslas). So let’s suppose there are 5,000 electric cars total.
You know (based on the 5,000 number) that you have at least 2,501 electric cars that are Red, and at most 2,499 electric cars that are NOT red. And, you also know you have 1,000 electric cars (i.e. Teslas). But how do you know that this 1,000 Teslas (electric cars) are either among the 2,501 red ones or the 2,499 non-red ones? The two premises don't guarantee that Teslas belong in the Red category, which is why you cannot say that some Teslas are red (what if they are actually among the 2,499 that are not red? It's possible: you have 2,499 non-red cars, which include the 1,000 Teslas).
It should be "most students in Professor Slughorn's class can brew potions masterfully . . ." The Slug Club is Professor Slughorn's club and only exists when he is the potions professor at Hogwarts.
I find Lawgic to be very confusing. The way I visualize these arguments in my head is giving priority to whichever one has all. If it is the case that all bars that serve fancy cocktails play loud music, all as in 100%, then obviously most of them serve wine play loud music. All overrides most. It makes much more sense than writing it out for me
seems like the bucket is helping people, but you can also do circles here again, to build off previous visuals. it’s not perfect, but i do better with static visuals vs the animated buckets.
most A are B = most of A circle intersects B circle.
all B are C = B is a subset of C, so the C circle completely surrounds B circle.
just imagine the C circle meets exactly at the B circle edge that’s inside A circle.
if all of B is inside C, then the A intersection is the same for B and C. most A are in B so most A are in C by default.
Most hippos can sing. All hippos that can sing fart glitter. therefore most hippos fart glitter . Hippos---m-->sing HIPPOS-->Fart G connect it : hippos--m->sing-->fart glitter conclusion hippos--m> fart g
Hmm, I am not sure if this is taught later or if this wouldn't be able to be a conclusion drawn, but If A-m->B would we then be able to conclude that B-s->A?
If most of A consists of B and all of B consists of C, then B and C are now inseparable and one in the same. So naturally, most of A must be C. I am looking at B and C interchangeably and one in the same.
54 comments
cant wait to be done with conditionals it feels like we've been learning about it for 2 years
#feedback It would be helpful if you would add an example that is "not valid", so we can compare.
Thanks for your feedback! I've shared your idea about a "not valid" example with our product team. We appreciate your input!
These videos make so much more sense than the set prior lol.
@kmartz I keep waiting for them to just start not making sense it seems too good to be true lol
@kmartz RIGHT
Respectfully Snape was never a potions professor when Slughorn was a professor. Thus, because I am a big fat nerd, the first argument is factually invalid.
#feedback I really like the bucket analogy, I would like to see more of it!
#feedback Add a "Let's Review" section like in all the other pages
Is there a way to get a summary of all 5 formal arguments?
There might be ways to trick someone here that people might want to watch out for. Let's take the first example:
Most students in Prof. Snape's class can brew potions masterfully. All students who can masterfully brew potions are invited to join the Slug Club. Therefore, most students in Prof. Snape's class are invited to join the Slug Club.
This works, is valid. But, if we just remove the modifier to "in professor Snape's Class" we change the domain, superset/subset relationship. whatever. We get:
Most students in Prof. Snape's class can brew potions masterfully. All students who can masterfully brew potions are invited to join the Slug Club. Therefore, most students are invited to join the Slug Club.
This would be invalid.
Very true!
Invalid because it's generalizing the students right? versus when it says in Prof. Snapes class you're specifically talking about his/her students..
that is correct. subtle wording change, but a totally different conclusion. great point in calling out!
#feedback It would be helpful to include a visual when including an analogy such as the bucket and scoop.
agree
The buckets saved my life.
#feedback venn diagrams (as used in past lessons) express these relationships more clearly than this convoluted 3-D bucket analogy.
Agreed! I always use them
the WHAT club???
I just wanted to say that the visual of the buckets is extremely helpful. It made the logic behind the argument so clear and I really appreciated it!
#feedback
it would be helpful to see an argument that is NOT valid. So we could see an example of how an invalid argument would be fed to us on the LSAT.
@EmilyMacaluso An example would be:
All Teslas are electric cars.
Most electric cars are red.
____________
Some Teslas are red --> WRONG conclusion.
We don't know which electric cars are red. The Teslas might all be among the minority that aren't red. It's possible, but not necessary — and logic only allows conclusions that are guaranteed by the premises.
To use numbers: say you have 1,000 Teslas. So you know you have 1,000 (at least) electric cars (from the first premise).
We don’t know how many electric cars exist in total, but clearly, it’s more than 1,000 (since not all electric cars are Teslas). So let’s suppose there are 5,000 electric cars total.
You know (based on the 5,000 number) that you have at least 2,501 electric cars that are Red, and at most 2,499 electric cars that are NOT red. And, you also know you have 1,000 electric cars (i.e. Teslas). But how do you know that this 1,000 Teslas (electric cars) are either among the 2,501 red ones or the 2,499 non-red ones? The two premises don't guarantee that Teslas belong in the Red category, which is why you cannot say that some Teslas are red (what if they are actually among the 2,499 that are not red? It's possible: you have 2,499 non-red cars, which include the 1,000 Teslas).
am i the only one that understood the lawgic and the minute he pulled out the buckets visual it made it confusing
Nope, I felt the same way. The logic checked out for me without the bucket visualization. This video could have been cut in half.
please add more explanations like the bucket example in other videos! this would be so helpful to me!
Thank God they sterilized the letter moving around like that was disturbing (though I still appreciated the effort to animate them).
It should be "most students in Professor Slughorn's class can brew potions masterfully . . ." The Slug Club is Professor Slughorn's club and only exists when he is the potions professor at Hogwarts.
Most books are paperback. All paperback books smell good. Therefore, most books smell good.
B ‑m→ P → SG
B ‑m→ SG
I find Lawgic to be very confusing. The way I visualize these arguments in my head is giving priority to whichever one has all. If it is the case that all bars that serve fancy cocktails play loud music, all as in 100%, then obviously most of them serve wine play loud music. All overrides most. It makes much more sense than writing it out for me
seems like the bucket is helping people, but you can also do circles here again, to build off previous visuals. it’s not perfect, but i do better with static visuals vs the animated buckets.
most A are B = most of A circle intersects B circle.
all B are C = B is a subset of C, so the C circle completely surrounds B circle.
just imagine the C circle meets exactly at the B circle edge that’s inside A circle.
if all of B is inside C, then the A intersection is the same for B and C. most A are in B so most A are in C by default.
Most hippos can sing. All hippos that can sing fart glitter. therefore most hippos fart glitter . Hippos---m-->sing HIPPOS-->Fart G connect it : hippos--m->sing-->fart glitter conclusion hippos--m> fart g
Hmm, I am not sure if this is taught later or if this wouldn't be able to be a conclusion drawn, but If A-m->B would we then be able to conclude that B-s->A?
who else went back to the spanish 101 question after this?
@ArthurMorgan I am Georgian for me it was RUSSIAN 101
If most of A consists of B and all of B consists of C, then B and C are now inseparable and one in the same. So naturally, most of A must be C. I am looking at B and C interchangeably and one in the same.
Is my reasoning correct?