@jos hahaha, coming back two months later, I can confidently say lawgic is second nature for me now! I took the Nov. LSAT and felt confident. Keep your head up, it will get easier :)
@cmonc093 they are usually still different concepts. Sure Luke is a Jedi, but if you bring in a different Jedi (Yoda? idk), you couldn't say that Yoda is a Luke. =, i guess, must refer to self-same things. Like you could say that Couch = Sofa, but i'm guessing that's never relevant to note
A couple years ago I told a math teacher that doing set theory was a waste of time and I wouldn't need it in my career. Well look at me now lol, its funny how things can come bite you later.
To me, this standard lawgic "formula" for valid conditional arguments is super helpful because it lets you easily spot an invalid argument, it's simply the argument that does not follow the standard
A --> B
X^A
-----
X^B
An example that I came up with that helped me picture all of this is "All cats are mammals. Jojo is a cat, therefore, Jojo is a mammal." This clearly follows the standard equation above. But if the argument is "All cats are mammals. Jojo is a mammal, therefore, Jojo is a cat" then the argument is invalid as it would be translated to
A --> B
X^B
----
X^A
There is a gap in the reasoning here and the conclusion (Jojo is a cat) does not follow from the premises (Jojo could be a dolphin, a dog, pig) therefore, it is invalid.
Are we supposed to do this type of diagramming/write out the formulas during the actual LSAT? Given the limited time per question this just seems way too time consuming. Surely there's other ways
@ujustgotlittup You might only want to do this for 1 or 2 questions in a section (the ones that have so many conditionals that it's hard to keep the connections in your head). The purpose of learning the structure now is so that it becomes more intuitive and that you can visualize most basic arguments in your mind. So typically you wouldn't draw anything out in a timed situation.
IDK if it's just me, but I feel like translating it into a more algebraic form is confusing me more. Maybe it's because I wasn't good at math in school, but it makes so much more sense to look at it visually or in English than in Lawgic form. I know they previously said it doesn't always work visually, but it just doesn't click in my head when I see it lawgically.
#feedback the whole subset/superset part of the lessons is a waste of time. If you were just going to introduce the classic arrow format anyway, why waste the time to establish an immediately useless method with the subsets?
I get what you mean. The whole super set thing confused my knowledge of sufficient and necessary relationship, but I think the previous section is more about visualizing what is going on abstractly? Idk for the supersets I was confused
@PhilipMorse the problem with this is that the arrows represent conditional statements which are like "if then" statements or "only if" statements. when you put L-->J what you are saying in "lawgic" literally translates to if luke then jedi. and with
L--->F what you are literally saying is if you are luke then you use the force. what you want to say luke is a jedi, and the way you state that is by a seperate premise which literally just says luke is a jedi, no conditional necessary. from that you can say okay, we have the first premise J--->F second premise Luke is a jedi, and with that you can conclude Luke uses the force. i hope this was helpful. look up Modus ponens. thats the form of this argument.
Just want to clarify for others. -> does not mean = . In the example he uses, if a Jedi, he can use force. DO NOT ASSUME, that if another statement claims that a person uses the force means that they are a Jedi, the claim only states that all Jedi can use Force, not the other way around. If I replaced Luke is a Jedi, with Luke uses the force, I can't make a valid argument and state that Luke is a Jedi
This was the error that he was warning us about earlier, right? The issue is that users of the Force is a superset of being a Jedi. So it is true that Luke, who is a member of the set of Jedis is therefore the member of the set of users of the Force. However, if someone else (say a generic Person A) is a user of the Force, this does not automatically mean they are a Jedi -- that the set of users of the Force is a superset of Jedis means that there are users of the Force who are not Jedis, and Person A could be a member of that group. To confuse the two would be making the error of confusing a necessary condition to be a sufficient one.
126 comments
I feel a skill builder would be great after this lesson to put everything into practice thus far.
Idk how I feel about this section... It reminds me of math and I'm terrible at math
@emmalc02 LMAOO foreal!
@jos hahaha, coming back two months later, I can confidently say lawgic is second nature for me now! I took the Nov. LSAT and felt confident. Keep your head up, it will get easier :)
Me, who flunked math in highschool:
anyone else think the letters and subscripts make it more confusing?
It only gets worse from here.
Yes!
In that case, I'll be wholeheartedly embracing this type of notation even though I hate it
@yanasok398 The letters make sense to me.. but why can't it be x=A, x=B...
@cmonc093 they are usually still different concepts. Sure Luke is a Jedi, but if you bring in a different Jedi (Yoda? idk), you couldn't say that Yoda is a Luke. =, i guess, must refer to self-same things. Like you could say that Couch = Sofa, but i'm guessing that's never relevant to note
A couple years ago I told a math teacher that doing set theory was a waste of time and I wouldn't need it in my career. Well look at me now lol, its funny how things can come bite you later.
If y'all are taking notes in Google Docs and are on a Max, Command and Comma is the shortcut for subscript!
Thank god for this lawgic language cuz the circles were freaking me out lol
To me, this standard lawgic "formula" for valid conditional arguments is super helpful because it lets you easily spot an invalid argument, it's simply the argument that does not follow the standard
A --> B
X^A
-----
X^B
An example that I came up with that helped me picture all of this is "All cats are mammals. Jojo is a cat, therefore, Jojo is a mammal." This clearly follows the standard equation above. But if the argument is "All cats are mammals. Jojo is a mammal, therefore, Jojo is a cat" then the argument is invalid as it would be translated to
A --> B
X^B
----
X^A
There is a gap in the reasoning here and the conclusion (Jojo is a cat) does not follow from the premises (Jojo could be a dolphin, a dog, pig) therefore, it is invalid.
i understood conditional argument clearer before we turned it into Algebra lol
Are we supposed to do this type of diagramming/write out the formulas during the actual LSAT? Given the limited time per question this just seems way too time consuming. Surely there's other ways
@ujustgotlittup You might only want to do this for 1 or 2 questions in a section (the ones that have so many conditionals that it's hard to keep the connections in your head). The purpose of learning the structure now is so that it becomes more intuitive and that you can visualize most basic arguments in your mind. So typically you wouldn't draw anything out in a timed situation.
IDK if it's just me, but I feel like translating it into a more algebraic form is confusing me more. Maybe it's because I wasn't good at math in school, but it makes so much more sense to look at it visually or in English than in Lawgic form. I know they previously said it doesn't always work visually, but it just doesn't click in my head when I see it lawgically.
@SheridanMcGadden A couple lessons later and I understand why we needs this now...
One who is a Soprano is Italian. Tony is a Soprano. Therefore, Tony is Italian.
S → I
t(S)
_
t(I)
#feedback the whole subset/superset part of the lessons is a waste of time. If you were just going to introduce the classic arrow format anyway, why waste the time to establish an immediately useless method with the subsets?
I get what you mean. The whole super set thing confused my knowledge of sufficient and necessary relationship, but I think the previous section is more about visualizing what is going on abstractly? Idk for the supersets I was confused
This is another way of teaching modus ponens, right?
Yes!!
not doing math so i don't confuse myself, ill be back once i finish everything to let you guys know if it was worth it or not
Wow - its chemistry class again :(
Instead of:
J ->F
L^J
L^F,
Wouldn't it be easier just to use:
J -> F
L -> J
L -> F ?
Maybe I'm splitting hairs and this is what works for me but someone lmk if me doing it this way will cause problems other conditions.
@PhilipMorse the problem with this is that the arrows represent conditional statements which are like "if then" statements or "only if" statements. when you put L-->J what you are saying in "lawgic" literally translates to if luke then jedi. and with
L--->F what you are literally saying is if you are luke then you use the force. what you want to say luke is a jedi, and the way you state that is by a seperate premise which literally just says luke is a jedi, no conditional necessary. from that you can say okay, we have the first premise J--->F second premise Luke is a jedi, and with that you can conclude Luke uses the force. i hope this was helpful. look up Modus ponens. thats the form of this argument.
@zakariaJannane ohhhh okay that helps a lot, thank you.
@zakariaJannane this was very helpful
Can't we just diagram it as J > F
L > J
Thus, L > F
(that way the J's cancel out, leading us to the conclsuion)
If you want to dive more deep into valid arguments and proofs. The book, “How To Prove It”, is a cool book on the subject.
It’s 2nd chapter is especially useful as you learn about (and ^) and (or) notation, which comes with drills. the drills have you turn sentences like:
“if it does not rain tommorow then it will snow” into logical structure.
Where R = rain, S = snow.
-R —> S (if NOT rain then snow).
It will either rain or snow. (R OR S)
-S
therefore R.
At minimum I’d hammer home DeMorgan’s Law:
P —> Q
-Q —> -P (valid)
-P —> -Q(invalid)
For AND^ operations:
(P ^ R) —> Q) if P and R then Q
-(P ^ R) —> -Q) if not P and R not Q
(-P OR -R) —> -Q) (OR flips ^ down)
if not P nor R not Q
Ok, so this is how I've been viewing it but idk if this helps or hurts me.
If one visits New Vegas then they see the Lucky 38. The courrier is in New Vegas. Thus, the courrier sees the Lucky 38.
V -) L
c(V)
_
c(L)
@11tristanseguin FNV reference!
@11tristanseguin BASED VALID ARGUMENT
I would suggest a more universal 'lawgic' to be:
A⟶B
x ∈ A
.'. x ∈ B
Just want to clarify for others. -> does not mean = . In the example he uses, if a Jedi, he can use force. DO NOT ASSUME, that if another statement claims that a person uses the force means that they are a Jedi, the claim only states that all Jedi can use Force, not the other way around. If I replaced Luke is a Jedi, with Luke uses the force, I can't make a valid argument and state that Luke is a Jedi
This was the error that he was warning us about earlier, right? The issue is that users of the Force is a superset of being a Jedi. So it is true that Luke, who is a member of the set of Jedis is therefore the member of the set of users of the Force. However, if someone else (say a generic Person A) is a user of the Force, this does not automatically mean they are a Jedi -- that the set of users of the Force is a superset of Jedis means that there are users of the Force who are not Jedis, and Person A could be a member of that group. To confuse the two would be making the error of confusing a necessary condition to be a sufficient one.
Is this wrong then?
J --> F
L--> J
______
L --> F
I was thinking more like this:
J-->F +
L-->J =
L-->J-->F =
L-->F
Does this hold up?