EVERY, EACH, ALL, SUFFICIENCY IN FUTURE?

[ivanperez16]

Anytime a stimulus uses the word "Every" "Each" or "All", there is always an inherent suggestion of conditionality...for example:

Each X is a Y
Every X is a Y
All X's are Y's

All statements Can be diagrammed as follows:

X Y

(if it's an X, then it's a Y)

But what if you modify a conditional statement about the past, as in:

In the past, ALL new discoveries have lead to hidden treasures.
Tomorrow, I will discover something new.
Therefore, I will find a hidden treasure tomorrow.



Is the conclusion valid or invalid?

Can you VALIDLY conclude that I will find a hidden treasure tomorrow, based solely on past instances of a modified "All" conditional statement?

...

As a golden rule, time shifts in the LSAT are usually wrong; you can't CONCLUSIVELY prove that something will occur again in the future if the only thing you know FOR SURE is what has been the case in the PAST (a mere correlation or fact pattern about history can't guarantee something with absolute certainty about the future, after all the LSAT is an exam concerned about what is the case every time and all the time, something that rests on complete certainty); but what if a conditional statement about the past is modified by a key word such as "Each", "Every", or "All"?

Do these Conditional Key Words ensure that what has been the case in the past is the case in the future? Do they act as Sufficient indicators even in the future tense?

Related to this idea,
are concept shifts such as in :

May Will
Likely Will
May not Cannot

"May" and "Will" are incompatible; "may" suggests a mere probability, but not complete certainty as "will" does
"Likely" and "will" are incompatible; "likely" suggests a fairly high probability, but not complete certainty as "will" does
"May not" and "cannot" are incompatible; "may not" suggests an ambiguous probability of may or may not occurring; "cannot" suggests a complete probability of something not occurring.



Any help understanding this will be great.

[jeff.wren]

Hi Ivan,

You're right that you can't conclusively prove that something will occur in the future based on what has happened in the past.

In your example, "In the past, ALL new discoveries have lead to hidden treasures" you cannot conclude that a new discovery will lead to hidden treasure tomorrow. Because of the qualifying language "in the past," the sufficient condition would be "New Discovery made in the past -> lead to a hidden treasure." New discoveries in the future would not satisfy this sufficient condition and therefore no inference can be made.

You are also correct that words like "may" (which conveys the idea of possibility) and "likely" (which conveys the idea of probability) do not indicate certainty. I would be cautious of thinking of the terms as incompatible. A better approach might be to think of them as expressing different levels of certainty. For example, a must be true answer (which is a certainty) is an acceptable answer to a could be true question. If something is certain to happen, then it is also possible.

I hope that this helps.

Best,
Jeff

[ivanperez16]

Dear Jeff:

Thanks for your feedback!
So what if I see the words 'may' and 'likely' in two parallel conclusions; would this be legitimate ground to render both 'may' and 'likely' as equivalent?

Would this be comparable in terms of strength if this were to appear in a conclusion? (of a Parallel question?)

[David Boyle]

Dear Jeff:

Thanks for your feedback!
So what if I see the words 'may' and 'likely' in two parallel conclusions; would this be legitimate ground to render both 'may' and 'likely' as equivalent?

Would this be comparable in terms of strength if this were to appear in a conclusion? (of a Parallel question?)

Hello ivanperez16,

No, "may" and "likely" don't really seem comparable. If you see them in two parallel conclusions, or one in the stimulus conclusion and another in one of the 5 answer conclusions for a parallel-reasoning question, it could be a trap.
For example, while I "may" flap my arms and fly to the moon (since there's a 1/200 trillion chance that a UFO may take pity on me and scoop me up to the moon), it's not *likely* that I'm going to get to the moon by flapping my arms. "Likely" pretty much means something with over a 50% probability, such as, the sun rising in the east tomorrow. instead of "going rogue" and rising in the west instead.

Hope this helps,
David