Some twentieth-century art is great art. All great art involves original ideas, and any art that is not influential ...

Ravi June 30, 2019

@izyat,

Happy to help. Let's take a look at (B).

This is a very diagrammable stimulus:

GA - some - 20th
GA - >Original ideas
not Influential - >not GA (GA - >Infuential)

From this, we can conclude that

20th - some - Original ideas
20th - some - Influential
Original ideas - some-Influential

Remember, we're looking for an answer choice that doesn't follow
logically from the stimulus. In other words, it could be false.

(B) says, "Some twentieth-century art involves original ideas."

(B) is an inference that we made, and this is something that follows
logically from the stimulus. It's not something that could be false,
so we can get rid of this choice.

(C) says, "Only art that involves original ideas is influential."

(C) is making the claim that original ideas are necessary for
influential art (Influential - >Original ideas). This is a very, very
strong iteration of the third inference we made above (Original
ideas - some - Influential), and it's something that certainly could be
false. Because it could be false, it's the correct answer choice.

Hope this helps. Let us know if you have any more questions!

m_salas12 July 1, 2019

Hi,

I have a question on how you're able to conclude OI-some-I (original ideas-some-influential) as they are both necessary conditions and I could not make a deduction from the quantifiers 20-some-OI and 20-some-I. I narrowed it down to C and A but got stuck there.

Luke February 14, 2020

All A's are B's
All A's are C's
Some B's are C's

hbanana100396 August 15, 2021

^ Can someone please confirm if @Luke's comment from 2/13/20 is valid?

I believe in the lesson it says you cannot combine "some" statements. So I don't understand how @Ravi 's explanation of ...

"20th - some - Original ideas
20th - some - Influential
Original ideas - some-Influential"

... makes sense?

But if @Luke is correct then I understand.

hbanana100396 August 15, 2021

^ Can someone please confirm if @Luke's comment from 2/13/20 is valid?

I believe in the lesson it says you cannot combine "some" statements. So I don't understand how @Ravi 's explanation of ...

"20th - some - Original ideas
20th - some - Influential
Original ideas - some-Influential"

... makes sense?

But if @Luke is correct then I understand.

Ravi February 7, 2022

@hbanana00396, yes, @Luke's comment is valid. If you have two all statements that share a sufficient condition, the necessary conditions of both statements have a "some" relationship with each other.