PT 53, (Dec 2007), Sec 1, #3 (Please help me understand this)

cbarker3241

I don't understand how B is the answer. In the lessons regarding weakening, I was under the impression that we were to look for ways to weaken the connection between the Premises and the Conclusion. If the question states that "many human diseases are genetically based," then how does B not just attack the Premises? I mapped out ... human diseases (HD) are genetically based (GB)... HD -> GB. Then some of Cat's (CG) genetics are the same to humans (HG). ... CG<--s--> HG. Then I said Some of Primates (PG) genetics are the same as Humans .... PG <--s--> HG... the conclusion is humans have many diseases (HD) in common with Cats (CD) ...HD --m-->CD

I figured (albeit I now see that it was an incorrect conclusion... I just dont know why) that the question was trying to jump from some cats and some primates genes are the same as humans so therefore Humans have diseases in common with Cats. Answer C could provide a weaker link with the premise/conclusion connection by pointing out that a some correlation does not imply a most correlation.

Any help or guidance would be appreciated.

Hibiscus

There wasn't any reason to map this out.

The science columnists states that the reason humans and cats have so many diseases in common is because cats are genetically closer to humans than any other mammals except nonhuman primates and that many human diseases are genetically based.

To weaken/defeat this argument, you have to prove that the diseases common between the two aren't genetically connected.

B states that most diseases common to both have no genetic basis, and is the answer we're looking for.

C states that they have more diseases in common with nonhuman primates than with humans. However, this doesn't defeat the explanation that genetics is the reason human and cat diseases are similar. C doesn't affect the argument at all, and is therefore a wrong answer choice.

cbarker3241

Thank you for helping me with your answer! I greatly appreciate the time.

I am still stuck though. I do understand how B functions as an answer; however, I think my question is now... how do I know when a weakening question is attacking the connection between the premises and conclusion or just attacking the premises themselves? It seems like two different objectives.

Thanks again for your help!