Law School Discussion

Nine Years of Discussion
;

Author Topic: How can a sufficient and necessary condition occur at the same time??  (Read 1235 times)

lawness

  • Sr. Citizen
  • ****
  • Posts: 262
    • View Profile
Well......how do they?? Any examples would be helpful!

PNym

  • Sr. Citizen
  • ****
  • Posts: 781
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #1 on: August 17, 2007, 11:04:12 PM »
Well......how do they?? Any examples would be helpful!

If you agree to testify against the Don, the DA will immediately drop all charges.

Lindbergh

  • Sr. Citizen
  • ****
  • Posts: 4358
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #2 on: August 17, 2007, 11:12:43 PM »

Graduating from law school is a necessary condition for getting a J.D.

It is also a sufficent condition for getting a J.D.


lawness

  • Sr. Citizen
  • ****
  • Posts: 262
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #3 on: August 17, 2007, 11:13:23 PM »
ahhhh I think I get it!! Any more would be very beneficial!!

lawness

  • Sr. Citizen
  • ****
  • Posts: 262
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #4 on: August 17, 2007, 11:21:41 PM »
Sorry for the lack of content. I just did not make the connection that both conditions can occur simultaneously. I thought one had to occur for the other to occur but I did understand that either can come first. So, basically a necessary condition can also be a sufficient condition and visa versa, right? In order for them to happen at the same time, I need to conceptualize the event co-occurring in my head. Is this correct?

lawness

  • Sr. Citizen
  • ****
  • Posts: 262
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #5 on: August 17, 2007, 11:36:36 PM »
Are there any statistics that speak to how often sufficient and necessary conditions occur simultaneously on the LSAT?

lawness

  • Sr. Citizen
  • ****
  • Posts: 262
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #6 on: August 17, 2007, 11:50:34 PM »
No, nothing in particular. I was just wondering. There seems to be a statistic for everything else! I feel confident in recognizing the relationship between the two conditions. The LSAT testmakers are real tricky in describing the conditional relationships. I have been learning the LRB strategies. Are there any other strategies out there that are helpful and easy to understand?

Lindbergh

  • Sr. Citizen
  • ****
  • Posts: 4358
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #7 on: August 18, 2007, 12:41:41 AM »
I don't recall any conditions on the LSAT that were both sufficient and necessary. 

Mabye an AB Block on the games would count. (A->B, B->A, so AB Block.) 

If you wanted to diagram it, just put the arrow going both ways.  But a block makes more sense.

But you're unlikely to see this on LR.

mantis

  • Sr. Citizen
  • ****
  • Posts: 683
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #8 on: August 18, 2007, 12:48:39 AM »
I don't recall any conditions on the LSAT that were both sufficient and necessary. 

Mabye an AB Block on the games would count. (A->B, B->A, so AB Block.) 

If you wanted to diagram it, just put the arrow going both ways.  But a block makes more sense.

But you're unlikely to see this on LR.

If you do see it on LR, it will probably be in the form of "if and only if" (ie. both sufficient and necessary).

moongirl6

  • Full Member
  • ***
  • Posts: 18
    • View Profile
Re: How can a sufficient and necessary condition occur at the same time??
« Reply #9 on: August 18, 2007, 05:00:10 AM »
I'm still not sure if Lawness is asking if a necessary condition and a sufficient condition can happen simultaneously (meaning that if these things were really happening, could they happen at the same time or does one have to come first), or if (s)he's asking if a necessary condition can also be a sufficient condition and vice versa--but here's something that might help regardless.  Logically speaking, 'necessary' and 'sufficient' are pretty much technical terms that refer to the logical relationship between two sentences/ideas, rather than to the actual relationship of whatever is being discussed.  In other words, here's a sentence:

If I have gas in my tank, then my car will run.

Even though in real life, it would be more accurate to say that gas is necessary for my car to run, in that sentence 'gas in my tank' is the sufficient part and 'my car will run' is the necessary part.  This is because 'necessary' just means "this is necessarily true if the other part is true"--which is what the conditional means.  And 'sufficient' just means "the truth of this statement is enough to guarantee the truth of this other statement".  The two statements that make up a conditional don't have to have any sort of realistic relationship at all--I can slap any two statements or ideas together and form a conditional, and one part will still be the sufficient part and the other the necessary part--so it might be easier not to think about how the statements are related to eachother in a real-life sense--because all any conditional really means is "if this is true, then that is true" -- why or how they are related to each other doesn't matter at all.