• Meaning: A clear, logical, and convincing argument.
• Example: A cogent argument is one that persuades the audience with clarity and rationality.
2. Sound:
• Meaning: An argument is sound if it is both valid (logically structured) and has true premises.
• Example: A sound argument guarantees that its conclusion is true.
3. Valid:
• Meaning: An argument is valid if the conclusion logically follows from the premises, regardless of the truth of the premises.
• Example: If the premises are true, the conclusion must be true in a valid argument.
4. Strong:
• Meaning: A strong argument is inductive, meaning that if the premises are true, the conclusion is likely to be true.
• Example: A strong argument increases the likelihood of the conclusion being true but does not guarantee it.
5. Inductive:
• Meaning: An argument where the premises provide probable support for the conclusion.
• Example: “Every swan I’ve seen is white, so all swans are probably white.”
6. Deductive:
• Meaning: An argument where the premises guarantee the conclusion if they are true.
• Example: “All humans are mortal. Socrates is human. Therefore, Socrates is mortal.”
7. Syllogism:
• Meaning: A form of deductive reasoning with two premises leading to a conclusion.
• Example: “All men are mortal; Socrates is a man; therefore, Socrates is mortal.”
8. Fallacy:
• Meaning: A flaw or error in reasoning.
• Example: A common fallacy is ad hominem, attacking the person instead of the argument.
9. Premise:
• Meaning: A statement or proposition from which a conclusion is drawn.
• Example: “All humans need water” is a premise leading to conclusions about human survival.
10. Conclusion:
• Meaning: The statement that logically follows from the premises in an argument.
• Example: From the premises “All humans need water” and “I am a human,” the conclusion is “I need water.”
11. Inference:
• Meaning: The process of deriving a conclusion based on evidence or premises.
• Example: If it’s cloudy, you might infer it’s going to rain.
12. Necessary Condition:
• Meaning: A condition that must be true for the conclusion to hold.
• Example: Oxygen is a necessary condition for fire.
13. Sufficient Condition:
• Meaning: A condition that guarantees the outcome.
• Example: Studying is a sufficient condition for passing a test (but not the only way to pass).
14. Refutation:
• Meaning: A counterargument or disproof of a statement or theory.
• Example: Pointing out contradictions in an opponent’s argument is a form of refutation.
15. Contradiction:
• Meaning: A situation in which two or more statements are logically incompatible.
• Example: Saying “The sky is blue” and “The sky is not blue” at the same time is a contradiction.
16. Tautology:
• Meaning: A statement that is true in every possible interpretation, often considered logically redundant.
• Example: “It will either rain tomorrow, or it won’t.”
17. Contrapositive:
• Meaning: The inverse of an implication statement where both the condition and result are negated.
• Example: The contrapositive of “If it rains, then I will stay home” is “If I do not stay home, then it did not rain.”
18. Biconditional:
• Meaning: A statement where both conditions imply each other (if and only if).
• Example: “You can have dessert if and only if you finish your dinner.”
19. Modus Ponens:
• Meaning: A logical rule stating that if “If A, then B” is true, and A is true, then B must also be true.
• Example: “If it rains, the ground will be wet. It is raining. Therefore, the ground is wet.”
20. Modus Tollens:
• Meaning: A rule of logic where if “If A, then B” is true, and B is false, then A must also be false.
• Example: “If it rains, the ground will be wet. The ground is not wet. Therefore, it did not rain.”
21. Dilemma:
• Meaning: A situation where two unfavorable options are presented, and you must choose one.
• Example: “Either I fail the exam, or I spend all night studying without sleep.”
22. Exclusive Disjunction (XOR):
• Meaning: A logical operator where one or the other condition is true, but not both.
• Example: “Either it will rain, or it will be sunny, but not both.”
23. Conjunction:
• Meaning: A compound statement formed by combining two statements with “and,” which is only true if both components are true.
• Example: “It is raining and it is cold” is only true if both conditions hold.
24. Disjunction:
• Meaning: A compound statement formed by combining two statements with “or.” It is true if at least one statement is true.
• Example: “It is raining or it is cold” is true if either condition is true.
25. Necessary and Sufficient Condition:
• Meaning: A necessary condition is something that must be true for an event to happen, while a sufficient condition guarantees the event.
• Example: Having a key is a necessary condition to open a door, while having a valid key and turning it in the lock is a sufficient condition to open it.
26. Inference:
• Meaning: A conclusion reached based on evidence and reasoning.
• Example: “The grass is wet, so it probably rained.”
27. Reductio ad Absurdum:
• Meaning: A form of argument where a proposition is disproved by showing that it leads to absurd or contradictory conclusions.
• Example: Arguing that if everyone ignored laws, chaos would ensue, proving the necessity of legal systems.
28. Quantifier:
• Meaning: Words like “all,” “some,” and “none” used in logical statements to indicate the extent of generalization.
• Example: “All cats are animals” vs. “Some cats are black.”
29. Non Sequitur:
• Meaning: A conclusion or statement that does not logically follow from the previous argument or statement.
• Example: “She drives a BMW, so she must be rich” (wealth does not necessarily follow from owning a BMW).
30. Equivocation:
• Meaning: A fallacy where a word is used in two different senses in an argument, leading to a false conclusion.
• Example: “The sign said ‘fine for parking here,’ so I thought it was okay to park” (confusing “fine” as in penalty with “fine” as in acceptable).
For those who chose A, I think the "charitable" interpretation overly confuses why its wrong. The author thinks both lines of reasoning are correct. The only thing "flawed" here is human perception. Not the lines of reasoning. Therefore, A fails to describe how the argument proceeds.
I feel like the LSAT writers always try to turn people away by throwing a crazy vocabulary word (like cogent) in the correct answer choice. I may be wrong but I feel like every time there is only one answer choice with a out of nowhere vocab word, 9/10 times that is the correct answer, especially if everything up until that word was making sense. They want you to see that word and skip it because you think "I don't know that word, therefore the answer doesn't make sense"
Me too. After watching the explanations, it seems that the main reason E is wrong is that these are not really "similar circumstances". The other point about books not being exactly "human cognitions" seems less persuasive to me and could be debated.
The first half does have a conclusion, but it isn't what the professor is trying to argue. They're using it as an analogy to support the second half. This is the main conclusion because the method of reasoning is that if the professor can establish that the 1st half is logically-sound, then the 2nd half, which follows the same logic, also makes sense. The "similarly" indicator helps because it implies that the professor has already laid the foundation for their conclusion and is now ready to drive the point home
JY absolutely love that you started off the video with "this is probably the hardest MOR question that we have come across". Got the question right and said "really" to this being the hardest.
good luck, ive been at it since december right now and im stuck at 160, i might drop 1000 on a tutor. Missing only 6 questions out of 75 is easier said than done.
every single word I don't know I make sure to learn; on answer choices in LR and especially RC if you misunderstand or scrap up either the stimulus or answer choice to unknown you will miss the correct answer choice
"Cogent" has a specific meaning in the study of formal logic. I would recommend becoming familiar with as many formal logic words and concepts as possible while preparing for the LSAT.
89 comments
who else learned the word cogent today
LOL yes!
i googled it when reading it lol
Googled it during BR and got it right.
got this one right but genuinely think it should be rated harder than a 3/5
1. Cogent:
• Meaning: A clear, logical, and convincing argument.
• Example: A cogent argument is one that persuades the audience with clarity and rationality.
2. Sound:
• Meaning: An argument is sound if it is both valid (logically structured) and has true premises.
• Example: A sound argument guarantees that its conclusion is true.
3. Valid:
• Meaning: An argument is valid if the conclusion logically follows from the premises, regardless of the truth of the premises.
• Example: If the premises are true, the conclusion must be true in a valid argument.
4. Strong:
• Meaning: A strong argument is inductive, meaning that if the premises are true, the conclusion is likely to be true.
• Example: A strong argument increases the likelihood of the conclusion being true but does not guarantee it.
5. Inductive:
• Meaning: An argument where the premises provide probable support for the conclusion.
• Example: “Every swan I’ve seen is white, so all swans are probably white.”
6. Deductive:
• Meaning: An argument where the premises guarantee the conclusion if they are true.
• Example: “All humans are mortal. Socrates is human. Therefore, Socrates is mortal.”
7. Syllogism:
• Meaning: A form of deductive reasoning with two premises leading to a conclusion.
• Example: “All men are mortal; Socrates is a man; therefore, Socrates is mortal.”
8. Fallacy:
• Meaning: A flaw or error in reasoning.
• Example: A common fallacy is ad hominem, attacking the person instead of the argument.
9. Premise:
• Meaning: A statement or proposition from which a conclusion is drawn.
• Example: “All humans need water” is a premise leading to conclusions about human survival.
10. Conclusion:
• Meaning: The statement that logically follows from the premises in an argument.
• Example: From the premises “All humans need water” and “I am a human,” the conclusion is “I need water.”
11. Inference:
• Meaning: The process of deriving a conclusion based on evidence or premises.
• Example: If it’s cloudy, you might infer it’s going to rain.
12. Necessary Condition:
• Meaning: A condition that must be true for the conclusion to hold.
• Example: Oxygen is a necessary condition for fire.
13. Sufficient Condition:
• Meaning: A condition that guarantees the outcome.
• Example: Studying is a sufficient condition for passing a test (but not the only way to pass).
14. Refutation:
• Meaning: A counterargument or disproof of a statement or theory.
• Example: Pointing out contradictions in an opponent’s argument is a form of refutation.
15. Contradiction:
• Meaning: A situation in which two or more statements are logically incompatible.
• Example: Saying “The sky is blue” and “The sky is not blue” at the same time is a contradiction.
16. Tautology:
• Meaning: A statement that is true in every possible interpretation, often considered logically redundant.
• Example: “It will either rain tomorrow, or it won’t.”
17. Contrapositive:
• Meaning: The inverse of an implication statement where both the condition and result are negated.
• Example: The contrapositive of “If it rains, then I will stay home” is “If I do not stay home, then it did not rain.”
18. Biconditional:
• Meaning: A statement where both conditions imply each other (if and only if).
• Example: “You can have dessert if and only if you finish your dinner.”
19. Modus Ponens:
• Meaning: A logical rule stating that if “If A, then B” is true, and A is true, then B must also be true.
• Example: “If it rains, the ground will be wet. It is raining. Therefore, the ground is wet.”
20. Modus Tollens:
• Meaning: A rule of logic where if “If A, then B” is true, and B is false, then A must also be false.
• Example: “If it rains, the ground will be wet. The ground is not wet. Therefore, it did not rain.”
21. Dilemma:
• Meaning: A situation where two unfavorable options are presented, and you must choose one.
• Example: “Either I fail the exam, or I spend all night studying without sleep.”
22. Exclusive Disjunction (XOR):
• Meaning: A logical operator where one or the other condition is true, but not both.
• Example: “Either it will rain, or it will be sunny, but not both.”
23. Conjunction:
• Meaning: A compound statement formed by combining two statements with “and,” which is only true if both components are true.
• Example: “It is raining and it is cold” is only true if both conditions hold.
24. Disjunction:
• Meaning: A compound statement formed by combining two statements with “or.” It is true if at least one statement is true.
• Example: “It is raining or it is cold” is true if either condition is true.
25. Necessary and Sufficient Condition:
• Meaning: A necessary condition is something that must be true for an event to happen, while a sufficient condition guarantees the event.
• Example: Having a key is a necessary condition to open a door, while having a valid key and turning it in the lock is a sufficient condition to open it.
26. Inference:
• Meaning: A conclusion reached based on evidence and reasoning.
• Example: “The grass is wet, so it probably rained.”
27. Reductio ad Absurdum:
• Meaning: A form of argument where a proposition is disproved by showing that it leads to absurd or contradictory conclusions.
• Example: Arguing that if everyone ignored laws, chaos would ensue, proving the necessity of legal systems.
28. Quantifier:
• Meaning: Words like “all,” “some,” and “none” used in logical statements to indicate the extent of generalization.
• Example: “All cats are animals” vs. “Some cats are black.”
29. Non Sequitur:
• Meaning: A conclusion or statement that does not logically follow from the previous argument or statement.
• Example: “She drives a BMW, so she must be rich” (wealth does not necessarily follow from owning a BMW).
30. Equivocation:
• Meaning: A fallacy where a word is used in two different senses in an argument, leading to a false conclusion.
• Example: “The sign said ‘fine for parking here,’ so I thought it was okay to park” (confusing “fine” as in penalty with “fine” as in acceptable).
Holy adderall
Thank you..."cogent"
cogent my butt
For those who chose A, I think the "charitable" interpretation overly confuses why its wrong. The author thinks both lines of reasoning are correct. The only thing "flawed" here is human perception. Not the lines of reasoning. Therefore, A fails to describe how the argument proceeds.
I feel like the LSAT writers always try to turn people away by throwing a crazy vocabulary word (like cogent) in the correct answer choice. I may be wrong but I feel like every time there is only one answer choice with a out of nowhere vocab word, 9/10 times that is the correct answer, especially if everything up until that word was making sense. They want you to see that word and skip it because you think "I don't know that word, therefore the answer doesn't make sense"
Thanks for this! Definitely a tip!
Yeah for me it's like, "I'm not 100% sure I know the meaning of that word, so it's probably safer to skip it"
I saw on a previous question someone commented " word, I do not even know what that means so I KNEW it was the answer"
What the hell is COGENT
I was able to get this right but I don't understand how you are supposed to know that the History argument is the main conclusion. I had it backwards
@JRS samee
E was looking real attractive and then I had to read it slowly
I am not entirely clear on why we know the second half is the main conclusion, and not an example supporting first statement
#feedback The handwriting is often complicated to understand, he should work on it.
I switched my answer I would have been right lol
same here. pain
Me too. After watching the explanations, it seems that the main reason E is wrong is that these are not really "similar circumstances". The other point about books not being exactly "human cognitions" seems less persuasive to me and could be debated.
good thing I've literally never heard the word cogent in my entire life
I had to look up what cogent means but I feel that it still counts that I got it right :))
The word Cogent did me in 😩
me too ahahhahaha
How many of us got this wrong specifically because of ‘cogent’?
Co Gent. Co means with. Gent is short for Gentleman. They're both gentlemen together. Oh my gawd the two arguments were roomates 😨
i got this right, but im confused as to how the second half is the main conclusion and the top half is not......
Just in case anyone else comes across this:
The first half does have a conclusion, but it isn't what the professor is trying to argue. They're using it as an analogy to support the second half. This is the main conclusion because the method of reasoning is that if the professor can establish that the 1st half is logically-sound, then the 2nd half, which follows the same logic, also makes sense. The "similarly" indicator helps because it implies that the professor has already laid the foundation for their conclusion and is now ready to drive the point home
had to quickly look up the word "cogent"... I feel dumb XD
missed this question because I misunderstood the word "cogent"
JY absolutely love that you started off the video with "this is probably the hardest MOR question that we have come across". Got the question right and said "really" to this being the hardest.
175 here I come!!!
good luck, ive been at it since december right now and im stuck at 160, i might drop 1000 on a tutor. Missing only 6 questions out of 75 is easier said than done.
This seemed more difficult than just a 3 for me
#feedback I had to look up the word "cogent" while answering this question... Is it worth it to practice certain vocabulary that shows up on the test?
every single word I don't know I make sure to learn; on answer choices in LR and especially RC if you misunderstand or scrap up either the stimulus or answer choice to unknown you will miss the correct answer choice
"Cogent" has a specific meaning in the study of formal logic. I would recommend becoming familiar with as many formal logic words and concepts as possible while preparing for the LSAT.
Picked A, was close to picking C ugh
I knew C was correct but of course did not choose C :)