71 comments

  • Monday, Jul 21, 2025

    i love you j.y. from 7sage, thanks for encouraging me to be over-confident. #parasocialrelationship

    43
  • Wednesday, Jun 14, 2023

    #feedback I understand these are lessons, however, it will be more helpful from experience using other sites and my progress in general if we can attempt the question before the lesson.

    27
    Thursday, Jul 25, 2024

    100% agree

    0
    Saturday, Sep 7, 2024

    use the quick view

    1
    Wednesday, Sep 11, 2024

    it was not available before

    1
  • Saturday, Sep 7, 2024

    I know it's been 100+ lessons but this is probably the first time the sufficiency necessity clicked

    21
    Monday, Sep 16, 2024

    LETS GOOOOOO

    2
    Tuesday, Sep 17, 2024

    dude literally me lol. the second i read it i was like wait did i actually understand s/n perfectly for once without second guessing

    1
  • Wednesday, Dec 4, 2024

    B tricked me with grammer, there was a must which indicated necessary.

    17
  • Monday, Aug 5, 2024

    #feedback for us taking notes, it would be really helpful to have a written "review" section of each lesson like the earlier LR lessons did. Definitely helps make sure I know what to internalize and understand

    16
  • Tuesday, Apr 16, 2024

    tbh the distinction between conditional and causal logic is useless for the LSAT. You never need to know that

    23
    Thursday, Jan 9, 2025

    Your observation is definitely correct. When I was studying logic in university for philosophy, we never made a distinction between the two in notation.

    1
    Tuesday, May 28, 2024

    agree! They always map the same

    5
    Tuesday, Jul 30, 2024

    Yeah this is a terrible take. Don't follow this advice unless you're happy in the 150s or 160s.. Knowing and applying the difference between conditional and causal logic will help you avoid all the wrong answers and time traps this dude is going to fall into.

    8
    Saturday, Jul 20, 2024

    You need to know the difference to be able to effectively solve any question on the LSAT that involves either of these argument types. For example, "if A then B" means that any time you have A you WILL have B. Causal logic will say "A causes B", which means that B occurred as a result of A. The conditional argument above is a sufficient argument, it guarantees B. Causal logic is a necessary argument. Furthermore, conditional arguments are easy to be valid, whereas causal arguments have a much higher bar to make valid because of their necessary nature. Understanding the difference between both of these arguments will help you solve EVERY type of question on the LSAT.

    13
    Monday, Jul 8, 2024

    I was also wondering about this. Can't we just classify the flaw in the stimulus as a mistaken negation of the sufficient and necessary ( A-->B , /A-->/B is invalid) and look for the same flaw in the AC instead of drawing this connection between causal and conditional? Is that what you mean by they "always map the same" ?

    0
    Tuesday, Jul 30, 2024

    The harder questions, those needed to break 170, absolutely depend on discerning whether the reasoning is causal or conditional. You'll sometimes have a conditionally worded question but the argument is chronologically structured, so it's actually a correlation/causation question. Then 3/5 answers are all conditionals, two are causal, but only one of them is actually chronological. I mean, to say that the distinction between the two is useless, it's just really setting up people to fail.

    4
    Tuesday, Jul 30, 2024

    To add onto my original response because of the validity part of it. A pure causal argument can never be valid, much like an argument by analogy, and that is yet another critical distinction between a conditional and causal argument.

    3
    Monday, Feb 3, 2025

    any tips on definitively telling the difference b/t conditional and causal?

    1
  • Saturday, Jan 11, 2025

    After some consideration, I realized that B is correct bc 'must' is a positive necessary indicator so the order of things is taste good --> right amount of flour

    10
  • Friday, Oct 4, 2024

    Not me doing a little dance after getting 4 questions right so far and I thought my formal logic skills were weak maybe I will be humbled in the future but time to dance for now.

    8

    Your comments make these lessons a bit more bearable lol

    1
    Wednesday, Oct 9, 2024

    This made my day :)) TYY

    0
  • Sunday, Dec 21, 2025

    im cooked

    14
  • Friday, Jul 10

    well well well, if it isn't our old friends sufficiency and necessary again

    7
  • Monday, Mar 30

    Saw "classic flaw" in the summary and guessed sufficiency/necessity confusion, I've grownnnn

    7
    Tuesday, Apr 14

    @tessapys exactly how I felt too when I recognized it haha!

    1
  • Edited Tuesday, Apr 7

    I hate this question I'm still confused b/w A and B.

    6
    Thursday, Apr 9

    @fart180

    The correct logic of the stimulus SHOULD BE:

    healthy bones --> sufficient calcium == sufficient calcium --> /healthy bones

    or

    A --> B == /B --> /A

    How the stimulus concludes it to be:

    healthy bones --> sufficient calcium == /healthy bones --> /sufficient calcium

    A --> B == /A --> /B

    We are looking to match the flawed logic of A --> B == /A --> /B within the answer choices

    A's logic (how the answer choice concludes it):

    firm crust --> right temp == /right temp --> /firm crust

    A --> B == /B --> /A

    This answer choice is logically sound. However, this means we have 2 absolute reasons why we know A is not correct now.

    1. We are looking for a FLAWED answer choice and A is not flawed.

    2. The logic of A --> B == /B --> /A does not match the stimulus which provided the flawed logic of

      A --> B == /A --> /B

    If A were to be correct it should have said "It therefore follows that bread that does not h

    B on the other hand is both flawed and follows the same reasoning/conclusion

    taste good --> right flour == /taste good --> /right flour

    1. This answer choice is FLAWED

    2. It matches the same chain of logic

    Therefore B is the correct answer.

    tldr: basically the stimulus provides a logic chain that is flawed. when i was doing the question I read that A had the same amount of conditions and structure but the conclusion was logically sound (not flawed) so A must be wrong. B on the other hand had the same condition and structure but the conclusion logic was flawed in the same structure as the stimulus.

    6
  • Saturday, Sep 13, 2025

    is there a lesson that shows the difference between causal and conditional?

    6
  • Wednesday, May 21, 2025

    I was so confused on this and it was annoying b/c it was so simple. I couldnt find the right answer and then went over again and realized I inccorectly mapped out B from the "must" indicator. The stim is A--->B /A----->/B, I had B mapped out as A----B /B---->/A and I was like wtf till I realzied the must and swapped it to /A---->/B and then made sense to why B is correct. The incorrect mapping is AC A.

    5
  • Tuesday, Jan 14, 2025

    With conditional causal logic, I like to conceptualize it as drinking alcohol and hangovers.

    hangover (effect) → drinking alcohol (necessary cause)

    /drinking alcohol → /hangover

    If someone told you that they didn't have a hangover this morning, would you automatically conclude they didn't touch alcohol last night? Obviously not. I had a liver of steel as a college student and simply did not get hangovers.

    Similarly, if I told you that I drank alcohol, you cannot conclude that I will definitively experience a hangover.

    Now let's look at sufficient causes.

    drinking a handle of vodka (sufficient cause) → alcohol poisoning (effect)

    Makes sense, right? Now unless you're superhuman, if you did NOT go to the ER then you can logically conclude that you did NOT drink an entire handle of vodka.

    /alcohol poisoning → /drinking a handle of vodka

    5
  • Monday, Jun 8

    I thought causal arguments couldn’t have contropostives. Is it because its in a If Then statement that if A-> B that /B->/A?

    4
  • Friday, Jun 5

    I am confused as to why I can't just use conditional logic for this question.

    4
    Wednesday, Jun 10

    @CaseySteffen I was confused about this too, but I think you can, he just uses cause effect to more quickly go through the answer choices. E.g. for C), if you look at the passage as solely conditional logic, you may try mapping out C) as if-then, but if you see the passage as cause-effect, then C) is obviously incorrect since there's no causal relationship in the first sentence. This is just a guess though since I had the same question.

    2
  • Wednesday, Feb 4

    I do not understand how the first sentence in B is correct is it reads cause > effect instead of effect > cause like the question

    4
    Thursday, May 7

    @CherishWilliams Great question. It is not what the sentence actually says but that IS how it is written. That's where the trick is: the sentence isn't written in the same IF->THEN format as the stimulus (but he didn't talk about that in the video or explanation; that's a miss for me).

    You could actually mentally rewrite the first sentence of B to to an IF THEN say:

    In order to taste good a cake must contain the right amount of flour.

    At that point you have A->B. Good.

    Now we need Taste Good -> Right Amount Flour for it to work. The second sentence says just that: It therefore follows that cakes that do not taste good do not contain the right amount of flour.

    I get why you missed it, and I think it would have been borderline diabolical if LSAC had included better answer choices to trick you but none of the other answer choices were alluring in a mean way, thankfully.

    1
  • Friday, Jul 4, 2025

    What if there were an answer choice that wasn't causal but nonetheless committed the same flaw of negating the sufficient condition (A→B, therefore, /A→/B)?

    4
  • Tuesday, Jan 21, 2025

    I don't see the difference between A and B...I thought it was A based that it said "If->then"

    4
    Friday, May 23, 2025

    A does not make the flaw that B does even though it is the same kind of argument.

    1
  • Sunday, Nov 3, 2024

    "in order to"

    B tricked me up on the grammar. I see it now.

    4
  • Friday, Jun 5

    When I read this the image not A- notB- came into my head lawwwgiicccc is paying off

    3
  • Friday, May 15

    Committed sufficiency - necessity confusion when I was mapping out B. If you're not careful, you might have made the same error. The first sentence of B doesn't read in the same order as the stim, so you have to make that connection before you map it.

    Ex. It's not (right amount of flour > taste good), it's (taste good > right amount of flour). You can help yourself out by rephrasing it like the stim does (If a cake is to taste good, it must contain the right amount of flour).

    3
    Wednesday, Jun 10

    @Willyc yeah it almost got me. the "must" saved me though so thank the conditional indicator gods

    1
  • Monday, Mar 16

    Anyone have helpful guides to know if a premise without key causal indicators is causal?

    3
    Friday, Mar 20

    This question specifically can be broken down simply with logic. I don't think you need a thorough understanding of causal vs. conditional to work through it.

    But in general, you can read this causal stim as:

    "If a thing is to happen, then it requires this thing to cause it."

    Whereas a conditional stim might read something like:

    "If an object looks like plop, then it must be a blorp."

    But for this question, just use simple arrows and you can get it right:

    p: Healthy Bones -> Calcium

    c: /Healthy Bones -> /Calcium

    This is flawed because nec/suff confusion. The only valid inference is the contrapositive /Calcium -> /Healthy Bones.

    AC B:

    A cake must (nec) contain the right amount of flour in order to (suff) taste good. It therefore follows that cakes that do not taste good do not contain the right amount of flour.

    Taste Good -> Right Flour

    /Taste Good -> /Right Flour

    Bingo, the flaw pattern matches the stim. Right answer. I didn't even once consider causal vs conditional.

    5
    Edited Monday, Mar 30

    @lollipoppy for myself, I consider any argument that involves change over time to be in the realm of causal reasoning. This doesn't mean you can infer a causal relationship. It means the reasoning is operating in the universe where causes happen, instead of, e.g., material conditional reasoning, which is about states and the truth value of those states.

    1
    Friday, Jul 10

    @gurbytown thanks for breaking this down, I missed the "must" on first reading so I had my sufficient and necessary condition transposed.

    1
  • Tuesday, Feb 4, 2025

    Can someone please explain why A is wrong and B is right. This is how I mapped it out:

    Question:

    Healthy Bones -> Sufficient Calcium (A->B)

    Not Healthy Bones -> Not Sufficient Calcium (NOT A -> NOT B)

    For answer choice A:

    Firm crust -> baked at right temp (A->B)

    Not baked at right temp -> not firm crust (Not B->Not A)

    For answer choice B:

    Right amount of flour -> taste good (A->B)

    Does not taste good -> not right amount of flour (Not B->Not A)

    are these not the same?

    3
    Thursday, Apr 3, 2025

    you mapped answer choice B wrong.

    its tastes good-> right amount of flour

    because the sentence states that a cake MUST (necessary indicator) contain the right amount of flour in order to taste good.

    from there you would map the conditional premise as A-> B and the conclusion is Not A-> Not B which matches the stimulus

    5
    Saturday, Feb 8, 2025

    The stim maps like this

    DHB = develops health bones

    DIC = Diet in calcium

    If DHB → DIC

    /DHB → /DIC

    This is a mistaken reversal as the actual contrapositive of the premise is

    /DIC → /DHB

    Thus the stim has flawed conditional reasoning!!

    AC A takes the contrastive properly — it is a sound argument

    AC B performs the same mistaken reversal as the stim and is thus the correct answer

    Your answer was incorrect because you accurately mapped the contrastive of the premise — the LSAt author did not!!

    5
    Friday, Aug 29, 2025

    @almond77 must introduces a sufficient condition/rule. So it's tastes good --> right amount of flour

    And the conclusion is /tastes good --> /right amount of flour which is the same flaw in the stimulus (mistaken reversal)

    A's conclusion is a contrapositive which is not really a flaw.

    0
    Tuesday, Nov 4, 2025

    @murphy.matt.j you're the GOAT for this explanation. I was having the same question and your explanation was so insightful!

    1

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