Propositional Logic: Necessary and Sufficient

This video show how to interpret the conditional logic of claims of the form "A is necessary for B" and "A is sufficient for B".

[mindfreakmovies]

I suspect that relation between necessary condition and sufficient condition with that of "if" and "only if" are correct. They are actually wrongly represented here.
*B if A* is translated A → B ( *sufficient* condition) i.e. B is true *if* A is true.
*B only if A* is translated B → A ( *necessary* condition) i.e. B is true *only if* A is true.

[davidlinehat]

Good video! I'm studying for the lsat and I'm stuck between trying to logically deduce the logic of a sentence and attempting to memorize what words/phrases indicate necessary and sufficent relationships. Your video was helpful

[therealmeteora]

Very helpful, nice illustrative examples, thank you!

[spacefacey]

thanks for the review! took two months off studying lsat after my august test and am not getting back on track for october!

[deepaksingh]

Thank u so much sir for explaining me both these conditions.

[LykkeNygaardJ]

I love your videos, but I am unsure why it says "A is necessary for B" at 1:47 while in your voice-over you say "B is necessary for A". The latter makes more sense to me, because if A is necessary for B in that example, then being rich would be necessary for being happy. But as you said yourself, being rich is not the only way to be happy. So it's not necessary. But to me it seems to be true that B is necessary for A. If the conditional as a whole is true, then I must necessarily be happy if I am rich.

I just rewatched it again, and you also said yourself "We can't say that A is necessary for B" at 1:21. Am I missing something obvious? Or is it an error that the written text says "A is necessary for B"?

[johnmahoney]

Just, thank you. It finally clicked watching your video.

[thetechguy]

Good explanation, i understood the concept of necessary and suffecient.

[jacealr]

I admire your channel. It is full of instructive videos

[michaelcaron]

Very good video kevin, one actually conjuring enough for me to observe the entire length of the video.But despite its unprecedented attraction, I'd have to admit that this video establishes to much emphasis on the basic structure of the conditional.there was a superb amount of information and knowledge supporting this cool edifice of logic, but why not dig deeper into the nucleus of using conditionals on truth tables, opposed to it's structure?perhaps a tour of the 5 ways to operate conditionals?

[Aiphiae]

If B then A - isn't that affirming the consequent?

[gokcesugokcek]

hi, can you explain what ıs the clear mean of necessary but not suffıcent?

[bentouatimohamedamine]

thnx to infinity you have saved my life

[gauravpande]

So, at 4:40 - The driver's license and test example has BOTH Necessary and Sufficient condition?

[michaelcaron]

It was a positively redundant introduction too the structure of this logical operator.Not once did i ever betray the superfluous objectiveness of this concept.

[michaelcaron]

But I do like the video.it presented loads of information on for those voyaging towards the art of rhetorically providing the structure of conditionals

[michaelcaron]

This is just some of my subjective view, please do not requisition it as discriminating materialistic feedback

[parizer]

I agree with Long Wei, example should have been better.

[michaelcaron]

by the way, I'd appreciate if you didn't take what a 13 year just said(me) but do consider taking the structuring function of a , and teaching a different component of the conditional. in addition, if you ever ace a thorough and complete explanation of the conditional you might perhaps, in continuation, give a "clear" presentation of biconditionals

[blankface]

You chose the worst one for the first example. Literally tons of rich people are unhappy