Unless v. Without Help - Multiple Conditions

Prepare for the LSAT or discuss it with others in this forum.
logicallogic

New
Posts: 12
Joined: Thu Aug 24, 2017 5:40 pm

Unless v. Without Help - Multiple Conditions

Postby logicallogic » Sat Aug 26, 2017 4:07 pm

Still struggling with understanding multiple conditions in negatively phrased sentences and properly extracting them into if/then format. Please assist with these two phrases (and explain why, if possible).

Sentence 1: Unless Joe has water and face paint, he cannot enter the event.

Sentence 2: The transition to a participant in the event cannot take place without water or face paint.

Please place these two sentences into if/then format along with contrapositives. And let me know if there is any logical difference whatsoever between without and unless.

Thanks in advance! Really trying to grasp the "rules" when dealing with these phrases.

B90

Silver
Posts: 563
Joined: Wed Sep 26, 2012 3:08 pm

Re: Unless v. Without Help - Multiple Conditions

Postby B90 » Sat Aug 26, 2017 4:17 pm

Unless = and; without = either
1) If Joe has no water and he has no face paint, then Joe won't enter.
2) If Joe is a participant, then he either has water or he has face paint.
When you form the contra-posive, "and" becomes "or"; "or" becomes "and"
So,
1) If Joe doesn't enter the event, then he doesn't have water OR he doesn't have face paint.
2) If no water AND no face paint, then Joe can't be a participant.

logicallogic

New
Posts: 12
Joined: Thu Aug 24, 2017 5:40 pm

Re: Unless v. Without Help - Multiple Conditions

Postby logicallogic » Sat Aug 26, 2017 5:02 pm

B90 wrote:Unless = and; without = either
1) If Joe has no water and he has no face paint, then Joe won't enter.
2) If Joe is a participant, then he either has water or he has face paint.
When you form the contra-posive, "and" becomes "or"; "or" becomes "and"
So,
1) If Joe doesn't enter the event, then he doesn't have water OR he doesn't have face paint.
2) If no water AND no face paint, then Joe can't be a participant.


B90, in the second phrase, why did you not render it (a) If participant, then water and facepaint, (b) if not water OR face paint, then not participant.

B90

Silver
Posts: 563
Joined: Wed Sep 26, 2012 3:08 pm

Re: Unless v. Without Help - Multiple Conditions

Postby B90 » Sat Aug 26, 2017 5:13 pm

logicallogic wrote:
B90 wrote:Unless = and; without = either
1) If Joe has no water and he has no face paint, then Joe won't enter.
2) If Joe is a participant, then he either has water or he has face paint.
When you form the contra-posive, "and" becomes "or"; "or" becomes "and"
So,
1) If Joe doesn't enter the event, then he doesn't have water OR he doesn't have face paint.
2) If no water AND no face paint, then Joe can't be a participant.


B90, in the second phrase, why did you not render it (a) If participant, then water and facepaint, (b) if not water OR face paint, then not participant.

Because having either water or face paint doesn't meet the condition.
WITHOUT = no water AND no face paint
OR = having one or the other would meet the condition.
In other words, with OR, there are 2 ways to meet the condition. WITHOUT means there is only 1 way to meet it; you need to have both.
This is an important distinction to understand for the lsat, because there are 2 LR sections (assuming it hasn't changed since I took it 5 years ago) and the lsat does like to trip you up on this distinction. :twisted:

logicallogic

New
Posts: 12
Joined: Thu Aug 24, 2017 5:40 pm

Re: Unless v. Without Help - Multiple Conditions

Postby logicallogic » Sat Aug 26, 2017 6:00 pm

B90 wrote:
logicallogic wrote:
B90 wrote:Unless = and; without = either
1) If Joe has no water and he has no face paint, then Joe won't enter.
2) If Joe is a participant, then he either has water or he has face paint.
When you form the contra-posive, "and" becomes "or"; "or" becomes "and"
So,
1) If Joe doesn't enter the event, then he doesn't have water OR he doesn't have face paint.
2) If no water AND no face paint, then Joe can't be a participant.


B90, in the second phrase, why did you not render it (a) If participant, then water and facepaint, (b) if not water OR face paint, then not participant.

Because having either water or face paint doesn't meet the condition.
WITHOUT = no water AND no face paint
OR = having one or the other would meet the condition.
In other words, with OR, there are 2 ways to meet the condition. WITHOUT means there is only 1 way to meet it; you need to have both.
This is an important distinction to understand for the lsat, because there are 2 LR sections (assuming it hasn't changed since I took it 5 years ago) and the lsat does like to trip you up on this distinction. :twisted:


Still tricky. Accepting your reasoning, then how are things altered the second phrase said: The transition to a participant in the event cannot take place without water AND face paint.

B90

Silver
Posts: 563
Joined: Wed Sep 26, 2012 3:08 pm

Re: Unless v. Without Help - Multiple Conditions

Postby B90 » Sat Aug 26, 2017 6:08 pm

logicallogic wrote:
B90 wrote:
logicallogic wrote:
B90 wrote:Unless = and; without = either
1) If Joe has no water and he has no face paint, then Joe won't enter.
2) If Joe is a participant, then he either has water or he has face paint.
When you form the contra-posive, "and" becomes "or"; "or" becomes "and"
So,
1) If Joe doesn't enter the event, then he doesn't have water OR he doesn't have face paint.
2) If no water AND no face paint, then Joe can't be a participant.


B90, in the second phrase, why did you not render it (a) If participant, then water and facepaint, (b) if not water OR face paint, then not participant.

Because having either water or face paint doesn't meet the condition.
WITHOUT = no water AND no face paint
OR = having one or the other would meet the condition.
In other words, with OR, there are 2 ways to meet the condition. WITHOUT means there is only 1 way to meet it; you need to have both.
This is an important distinction to understand for the lsat, because there are 2 LR sections (assuming it hasn't changed since I took it 5 years ago) and the lsat does like to trip you up on this distinction. :twisted:


Still tricky. Accepting your reasoning, then how are things altered the second phrase said: The transition to a participant in the event cannot take place without water AND face paint.

Because your sentence 2 said without water OR face paint. That becomes no water AND no face paint when you form the contra-positive (you have to reverse and then negate the phrases).

bcjets212

New
Posts: 18
Joined: Wed Nov 05, 2008 12:35 am

Re: Unless v. Without Help - Multiple Conditions

Postby bcjets212 » Sat Aug 26, 2017 10:17 pm

B90 wrote:Unless = and; without = either
1) If Joe has no water and he has no face paint, then Joe won't enter.
2) If Joe is a participant, then he either has water or he has face paint.
When you form the contra-posive, "and" becomes "or"; "or" becomes "and"
So,
1) If Joe doesn't enter the event, then he doesn't have water OR he doesn't have face paint.
2) If no water AND no face paint, then Joe can't be a participant.



Sorry, but multiple parts of this are not correct. Unless reflects a negative sufficient (i.e. synonymous with the phrase "if not"), but for #1 that would make it "If joe has no water OR he has no face paint, then joe won't enter".

Further, for contra's you have to negate BOTH SIDES, so it becomes "If joe enters, then he has water and he has face paint."


In terms of the logical difference between Unless and Without, there are none. Grammatically there is different uses, but logically they are the same. And to that, your representations of sentence 2 are correct.

pricon

Bronze
Posts: 162
Joined: Sat Aug 05, 2017 4:05 pm

Re: Unless v. Without Help - Multiple Conditions

Postby pricon » Mon Aug 28, 2017 11:01 am

Just memorize the transforms:

The idea following "unless": turn negative and make sufficient. Thus, "If Joe does not have water and face paint, then he cannot enter the event."
Sufficient: "If Joe does not have water and face paint . . ."
Necessary: ". . . then he cannot enter the event."

The idea following "without": turn negative and make sufficient. Thus, "If there is no water or face paint, then the transition to a participant in the event cannot take place."
Sufficient: "If there is no water or face paint. . ."
Necessary: ". . . then the transition to a participant in the event cannot take place."

"Without" and "unless" are logical equivalents.

Now, you just have to deal with multiple conditions in non-negatively phrased sentences. Can you do that?

pricon

Bronze
Posts: 162
Joined: Sat Aug 05, 2017 4:05 pm

Re: Unless v. Without Help - Multiple Conditions

Postby pricon » Mon Aug 28, 2017 11:01 am

B90 wrote:Unless = and; without = either
1) If Joe has no water and he has no face paint, then Joe won't enter.
2) If Joe is a participant, then he either has water or he has face paint.
When you form the contra-posive, "and" becomes "or"; "or" becomes "and"
So,
1) If Joe doesn't enter the event, then he doesn't have water OR he doesn't have face paint.
2) If no water AND no face paint, then Joe can't be a participant.


OP, ignore this advice.

Andersblooms93

New
Posts: 20
Joined: Thu May 25, 2017 11:00 am

Re: Unless v. Without Help - Multiple Conditions

Postby Andersblooms93 » Mon Aug 28, 2017 11:34 am

[quote="logicallogic"]Still struggling with understanding multiple conditions in negatively phrased sentences and properly extracting them into if/then format. Please assist with these two phrases (and explain why, if possible).

Sentence 1: Unless Joe has water and face paint, he cannot enter the event.
Anything introduced by 'unless' is a necessary condition, you then proceed to negate the other conditional element of the statement.
You are thus left with, "If he enters the event then Joe has water and face paint." CP: If Joe doesn't have water OR face paint then he doesn't enter the event.

Sentence 2: The transition to a participant in the event cannot take place without water or face paint.
Without is a temporal logical equivalent for unless. Same rules apply as above.
IF the transition to a participant in the event can take place then there is water or face paint.
CP: If there is no water AND no face paint (LSAT will tend to phrase this as: if there is neither water or face paint) then the transition to a participant in the event cannot take place.

logicallogic

New
Posts: 12
Joined: Thu Aug 24, 2017 5:40 pm

Re: Unless v. Without Help - Multiple Conditions

Postby logicallogic » Tue Aug 29, 2017 12:45 am

Andersblooms93 wrote:
logicallogic wrote:Still struggling with understanding multiple conditions in negatively phrased sentences and properly extracting them into if/then format. Please assist with these two phrases (and explain why, if possible).

Sentence 1: Unless Joe has water and face paint, he cannot enter the event.
Anything introduced by 'unless' is a necessary condition, you then proceed to negate the other conditional element of the statement.
You are thus left with, "If he enters the event then Joe has water and face paint." CP: If Joe doesn't have water OR face paint then he doesn't enter the event.

Sentence 2: The transition to a participant in the event cannot take place without water or face paint.
Without is a temporal logical equivalent for unless. Same rules apply as above.
IF the transition to a participant in the event can take place then there is water or face paint.
CP: If there is no water AND no face paint (LSAT will tend to phrase this as: if there is neither water or face paint) then the transition to a participant in the event cannot take place.


Thank you so much. One follow up: what do you mean by "temporal" as pertaining to without? Are you saying that when "without" is used there is an implication that the timing/order of events is important in a way not suggested by "unless"? Please elaborate!

Andersblooms93

New
Posts: 20
Joined: Thu May 25, 2017 11:00 am

Re: Unless v. Without Help - Multiple Conditions

Postby Andersblooms93 » Tue Aug 29, 2017 1:54 am

Without can signify 'unless' in a situation implicating time (hence I said temporal)...a better way of thinking about it is that "unless" is functionally equivalent to "without" and vice versa. Quite simply, their logical implication when situated in a conditional sufficient/necessary condition is the same. Put in even more simple terms: treat them like synonyms for the purposes of the LSAT.

logicallogic

New
Posts: 12
Joined: Thu Aug 24, 2017 5:40 pm

Re: Unless v. Without Help - Multiple Conditions

Postby logicallogic » Tue Aug 29, 2017 4:38 pm

Andersblooms93 wrote:Without can signify 'unless' in a situation implicating time (hence I said temporal)...a better way of thinking about it is that "unless" is functionally equivalent to "without" and vice versa. Quite simply, their logical implication when situated in a conditional sufficient/necessary condition is the same. Put in even more simple terms: treat them like synonyms for the purposes of the LSAT.


I full appreciate and understand that these should be treated as synonyms for purposes of the LSAT. But I am more curious in a general/theoretical sense as to the distinction you made. Hoping to get some more information in that direction--so don't worry about confusing me for LSAT purposes!

You stated: "Without can signify 'unless' in a situation implicating time (hence I said temporal)..." Thus, are you saying that using "without" is technically more appropriate/accurate than "unless" in situations which specifically involve time? Please elaborate. And feel free to provide a link/other material with some more information that makes that "temporal" distinction. I understand it is subtle, doesn't change the logical equivalence, etc. but the distinction you made is very important from my particular standpoint.

Thank you in advance, Andersblooms93!



Return to “LSAT Prep and Discussion Forum�

Who is online

Users browsing this forum: Google [Bot], Google Adsense [Bot] and 19 guests