Distinguishing And Vs. Or

[JD180]

I am having some difficulty distinguishing between some key nuances here:

"Any language learned by the linguist or paleontologist is not learned by the geologist."

Can you help me write a conditional statement for this? To demonstrate that I'm putting in work myself, here's my thought process:

For this, Would the conditional diagram look like:

Langp
or --> /LangG
LangL

If my conditional is correct (not sure if it is, and I'm not sure if I'm even allowed to make a conditional here, and I'm confusing the crap out of myself), Doesn't this have some ambiguity involved, since we don't know if its P's languages or L's Languages (or both) that G doesn't know? In other words, I would think that I'm not allowed to to break this conditional into individually cogent conditionals:

Langp --> /LangG
LangL --> /LangG
LangP and LangL --> /LangG

Due to the OR statement, the above 3 on their own aren't correct necessarily, since the languages of the P could also be known by G, but instead its the languages known by L that cannot be known by G. And vice versa. Also, since it is an OR statement initially, it is possible (but not necessarily true) that the all languages known by P and L together are not known by G.

But as a reader, we don't know if its one, or the other, or both. If all I'm saying is right, then I get confused by the following:

"If Josh is excited or medicated, he is content."

E
or --> C
M

Here I think we could write, unlike the previous quote:

E-->C
M-->C
E and M --> C

So I'm pretty confused.

Here's another:

"If operations or sales is offered, then accounting is also offered."

This is also an OR statement:

O
or --> A
S

For this one, I feel that we could also write as separately cogent conditionals:

O-->A
S-->A
O and S --> A


"If jays, martins, or both are in the forest, then so are harriers."

This had me put:

J
or --> H
M

(the "Both" almost threw me off, but that's inherently possible in an or statement, so he could equally have just said "if Jays or martins are in the forest, then so are harriers" he would be getting across the same point exactly, and "both" wasn't needed. is this right?)

I feel like here I could write:

Jays --> Harriers
Martins --> Harriers
Jays and Martins --> Harriers

All in all, I think it might be evident that I don't understand much here.

[Dave Killoran]

I'm going to start with two links that will help:

Diagramming LSAT Conditional Statements 101: "Or" in the Sufficient Condition

Diagramming LSAT Conditional Statements 101: "And" in the Necessary Condition

those cover at least some of your questions.

[JD180]

I'm going to start with two links that will help:

Diagramming LSAT Conditional Statements 101: "Or" in the Sufficient Condition

Diagramming LSAT Conditional Statements 101: "And" in the Necessary Condition

those cover at least some of your questions.

Hi Dave, I've read the LR bible as well as those posts, so I'm pretty good at using ands and ors, but for that first statement in my post, it's giving a lot of trouble.

[Dave Killoran]

Hi JD,

Thanks for the followup! The way most people diagram this rule is similar to the way you did originally (and I'll simplify it here and just refer to the researchers, but we know it's about the languages):

• L
  or G
  P

Now, as noted in the link, the use of "or" in the sufficient condition does indeed allow for separation into separate, component statements:

• L G
  
  
  P G

So, what's the functional outcome of how this works together? It may seem contradictory, but the "any...or" in the sufficient condition actually results in a situation where the languages of "both" are the basis for the full sufficient condition. The key is that "any" language learned by L or P cannot be learned by G. So, if one of them learns a language, G cannot learn that same language. This is actually revealed by our ability to separate the original statement into two separate standalone statements, since each statement alone is always true, meaning both are in force. Let's look at an example to see how it works:

• Let's say that the Linguist learns R and Y, and the Paleontologist learns T and Y.
  
  When L learns R and Y, according to the "Any language learned by the linguist" portion we know G cannot learn those two languages. But it's also the case that the same thing occurs with the languages learned by P, meaning that G is effectively barred from all three of R, T, and Y.

I know you are saying, "but is it the language learned by L or P that we have to worry about?" but that's not how it works when "or" is in the sufficient condition (a point highlighted by the sweeping power of "any" in the rule).

Thanks!

[JD180]

Hi JD,

Thanks for the followup! The way most people diagram this rule is similar to the way you did originally (and I'll simplify it here and just refer to the researchers, but we know it's about the languages):

• L
  or G
  P

Now, as noted in the link, the use of "or" in the sufficient condition does indeed allow for separation into separate, component statements:

• L G
  
  
  P G

So, what's the functional outcome of how this works together? It may seem contradictory, but the "any...or" in the sufficient condition actually results in a situation where the languages of "both" are the basis for the full sufficient condition. The key is that "any" language learned by L or P cannot be learned by G. So, if one of them learns a language, G cannot learn that same language. This is actually revealed by our ability to separate the original statement into two separate standalone statements, since each statement alone is always true, meaning both are in force. Let's look at an example to see how it works:

• Let's say that the Linguist learns R and Y, and the Paleontologist learns T and Y.
  
  When L learns R and Y, according to the "Any language learned by the linguist" portion we know G cannot learn those two languages. But it's also the case that the same thing occurs with the languages learned by P, meaning that G is effectively barred from all three of R, T, and Y.

I know you are saying, "but is it the language learned by L or P that we have to worry about?" but that's not how it works when "or" is in the sufficient condition (a point highlighted by the sweeping power of "any" in the rule).

Thanks!

Perfect this makes sense now.