Law School Discussion

Nine Years of Discussion
;

Author Topic: Sufficient and Necessary Conditions  (Read 323 times)

Commie Panda

  • Sr. Citizen
  • ****
  • Posts: 869
  • Don't worry, I'm not really a commie...or a panda
    • View Profile
Sufficient and Necessary Conditions
« on: December 06, 2005, 02:11:29 AM »
Now, according to Powerscore's LGB, a necessary condition needs to be true for a sufficient condition to occur. So, for example, "I need to study to do well on the LSAT" can be written out as:

Do well on the LSAT--> Study...right?

However, the following is from the Powerscore site:

"If you are rich or famous, then you are happy"
Rich or famous-->happy
Being happy is the sufficient condition...so you need to be rich or famous (necessary) to be happy.

I'm just confused as to why in my example, the sufficient condition comes first, and in this example off the Powerscore website, the necessary condition comes first...??

Does someone have a quick and easy way to explain diagramming conditional statements? I'm usually quite good with these and their contrapositives but sometimes the more I analyze them, the more confused I become.

------

2) While going over an LR question, one of the answer choices was as follows:

"Prior experience in foreign affairs is neither a sufficient nor a necessary condition for a president or prime minister to have a successful foreign policy"

The wording just seemed strikingly similar to the way the LGB describes conditional statements, but I take it, it was just saying that to have a successful foreign policy having prior experience alone is not sufficient in and of itself, and also is not necessary.

I realize I answered the question I posed to everyone myself, but that wording just seemed confusingly similar to the LGB terminology of "sufficient" and "necessary" conditions.


------




sea dream

  • Sr. Citizen
  • ****
  • Posts: 773
    • View Profile
Re: Sufficient and Necessary Conditions
« Reply #1 on: December 06, 2005, 02:15:57 AM »
if you are rich or famous, then you are happy..

this means that the sufficient condition is actually rich or famous. think about it. they're saying that as long as you are rich or famous, you must be happy. not that you must be rich or famous to be happy. Happy is what follows necessarily from being rich or famous in that statement. not that if you are happy you must be rich or famous. that would make happy the sufficient condition.
Nevermind. Queen of the Waitlists, anyways.

Commie Panda

  • Sr. Citizen
  • ****
  • Posts: 869
  • Don't worry, I'm not really a commie...or a panda
    • View Profile
Re: Sufficient and Necessary Conditions
« Reply #2 on: December 06, 2005, 02:23:06 AM »
Thanks SeaDream...The way it was written confused me but yes rich or famous is the sufficient condition.

Here's where I got it from:
http://www.powerscore.com/lsat/help/multiple.htm

sea dream

  • Sr. Citizen
  • ****
  • Posts: 773
    • View Profile
Re: Sufficient and Necessary Conditions
« Reply #3 on: December 06, 2005, 02:24:33 AM »
Thanks SeaDream...The way it was written confused me but yes rich or famous is the sufficient condition.

Here's where I got it from:
http://www.powerscore.com/lsat/help/multiple.htm

Yeah, i see how you were confused.,. the part about meeting the sufficient condition threw me off for a bit too. but as you probably saw it was actually in reference to fulfilling the condition because their example was you must be both rich AND famous = sufficient condition.
Nevermind. Queen of the Waitlists, anyways.

Commie Panda

  • Sr. Citizen
  • ****
  • Posts: 869
  • Don't worry, I'm not really a commie...or a panda
    • View Profile
Re: Sufficient and Necessary Conditions
« Reply #4 on: December 06, 2005, 02:26:46 AM »
yup, that's where my confusion lay.