Sufficiency and necessity vs Premise and conclusion.

Lsatbreakingnews

What is the overlap between these two concepts? It seems like answer choices need to be on a certain side of the arrow to be correct.

tanes256

That is correct. SA and NA questions are asking for different things. SA (what would have to happen to trigger the conclusion) is left side of arrow and NA (just enough to guarantee the conclusion) is right side of arrow. AC may have the other to throw you off. Are you having an issue determining SA and NA? They are both premises, not conclusions. Premises support conclusions.

Lsatbreakingnews

@tanes256 said:
That is correct. SA and NA questions are asking for different things. SA (what would have to happen to trigger the conclusion) is left side of arrow and NA (just enough to guarantee the conclusion) is right side of arrow. AC may have the other to throw you off. Are you having an issue determining SA and NA? They are both premises, not conclusions. Premises support conclusions.

No im okay with SA questions. I think I need some clarification/lesson on when which answer will go on which side I guess. For example in MBT and principle questions where there are conditional statements I would like to have some more info on when to choose which answer.

quinnxzhang

Sufficient and necessary conditions are features of conditional statements ("if P, then Q"), whereas premises and conclusions are features of arguments ("P. Therefore, Q").

In classical logics, there's something called the deduction theorem (https://en.wikipedia.org/wiki/Deduction_theorem) which intimately relates these two things, i.e. "if P, then Q" is valid iff "P. Therefore, Q" is valid.

On the LSAT, you won't really need to understand this nuance. Sufficient conditions are analogous to premises, and necessary conditions are analogous to conclusions. They're not exactly the same (conditional statements are truth-apt, arguments aren't), but conceptually, it may help to understand the analogy between the two.

Lsatbreakingnews

@quinnxzhang said:
In classical logics, there's something called the deduction theorem (https://en.wikipedia.org/wiki/Deduction_theorem) which intimately relates these two things, i.e. "if P, then Q" is valid if and only if "P. Therefore, Q" is valid.

That is way too crazy for me to understand hahaah.

@quinnxzhang said:
On the LSAT, you won't really need to understand this nuance. Sufficient conditions are analogous to premises, and necessary conditions are analogous to conclusions.

Okay so there is no way to know that a sufficient condition has occured then. Only that it has not occured. And we cannot conclude something if it is not in the necessary condition? Im confused as f**** about something but im not exactly sure what. ahaha.

Lsatbreakingnews

If anyone else has something to add please do!

tanes256

@Euthyphro look at the sufficient and necessary conditions cheatsheet in the curriculum. Is that what you mean by knowing that a sufficient or necessary condition has occurred? I don't think we get exactly what you're needing help with. @quinnxzhang is spot on though. You just need a more simplistic explanation.