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 Johnclem
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#26853
Hi
quick question for this one! is D wrong because it's a reversal or because it could be ?
-I'm confused because I though the necessary consdition could occur without its sufficient buddies.


Participate in local politics --> interested in public service & selfish opportunists --> influence In local politics



D) some of those who influence the community's values neither are interested in public service nor are selfish opportunists .


Thanks
John
 Clay Cooper
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#26863
Hi johnclem,

Thanks for your question.

I will talk about why D is wrong - I'm a little confused by your diagramming and get a bit lost after you ask why D is wrong, so I will deal with that, and you can let me know if I haven't answered your question.

Answer choice D is incorrect because we can't prove that is is true (or, in your words, it only COULD be true); it is not the case that D must be true.

We are told that everyone that participates in local politics has an impact on the community's values:

participate in local politics :arrow: influence on community's values

We are also told that among those who participate in local politics, there are people who are interested in public service, and also people who are selfish opportunists. We are NOT told, however, that everyone that participates in local politics must be one or more of these two things. For instance, it could be the case that Bob participates in local politics, and is neither a selfish opportunist nor interested in public service, but just too bored to sit at home. Such a situation is in accordance with our evidence, but not with answer choice D; therefore, it is not the case that D must be true.

Does that clarify why D is incorrect?
 Johnclem
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#26896
Oh my .
I just thought statements like" people who," " those who " indicate a sufficient condition. Which is why I diagrammed the stimulus into one big chain. So if I am understanding correctly, the only conditional statement in this stimulus is the last sentence ? :-? And the first sentence is a some statement rather than an all statement . But if that's the case , then how is A a must be true? ( especially if it doesn't have to be the case that there are people who are selfish opportunities ) I am very lost now.

And came up with this diagram

Participate in local politics < some > interested in public service & selfish opportunists
Participate in local politics --> influence on the community's values.


Thank you
John







Thanks
John
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 Jonathan Evans
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#26906
Hey John,

You've got a lot going on here, so let's break it down! First, yes, "people who" and "those who" do indicate a possible sufficient condition. However, the operative word here is the verb "include" rather than the alternate phrasing "are...either"

i.e. "Those who participate in local politics include people who are genuinely interested in public service and people who are selfish opportunists." is different from "Those who participate in local politics are either genuinely interested in public service or are selfish opportunists but not both." The latter statement gives you a sufficient condition. The former statement just tells you that some subset of those who participate in local politics fit into these two groups.

Now, (A) indeed must be true. Since we know that among those who participate in local politics, there is at least one selfish opportunist and we know that everyone who participates in local politics has an influence on the community’s values, we can put those two statements together to prove that the selfish opportunist who participates in local politics definitely has an influence on the community's values.

Your diagrams of these statements are fine, but make sure you're not adding extra layers of complexity to these problems. I hope this helps. Please follow up with further questions.
 bk1111
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#38527
This might be a silly question - but sometimes I get confused about whether phrases like "include people who are genuinely interested in public service and people who are selfish opportunists" should be diagrammed as individual conditionals or together.

For example, I was almost tempted to diagram this as local politics :arrow: genuinely interested & selfish opportunists rather than two separate ones: local politics :some: genuinely interested and local politics :some: selfish opportunists

This also occurred during PT 43 Section 2, #17:

"No small countries and no countries in the southern hemisphere have permanent seats on the UN Council"

Am I missing something grammatical here? Thank you for your explanation....
 Adam Tyson
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#38542
I see what's drawing you in there, bk - the presence of "people who". But that is a sufficient condition indicator ONLY IF there is also some necessary condition paired with it! When we say "people who", we are identifying a group of some sort - people who like anchovies, people who live in rural communities, people who have orange skin, etc. To make it a conditional claim, we have to then say that the member of the group have a certain characteristic: "People who like anchovies also like olives".

In this question, we get no necessary condition, as we are not told that the people who are in those groups all have certain characteristics. Instead, we get that the members of the group (participating in local politics) may also belong to other groups. We don't get told anything about ALL of the people in local politics, or ALL of the selfish people, or ALL of the genuinely interested people. It's just that one group has members that may also be in other groups. In fact, we don't know that those two subgroups make up all of the people involved in local politics. That group includes the second two groups, but maybe it also includes people who are just bored and looking for something to do? People trying to meet new friends? People who were ordered to get involved as a condition of their community service? "A includes some B" is not conditional, but is rather a statement involving the closely related concept of Formal Logic.

In your second example, though, we definitely have a conditional relationship. We know that IF you are a small country or IF you are a country in the southern hemisphere THEN you are not on the security council. The members of those two groups all have a certain characteristic. Diagram that, think about the contrapositive, and you'll be in good shape.

I hope that illustration of the difference between those types of statements helps!
 bk1111
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#38580
Adam Tyson wrote:I see what's drawing you in there, bk - the presence of "people who". But that is a sufficient condition indicator ONLY IF there is also some necessary condition paired with it! When we say "people who", we are identifying a group of some sort - people who like anchovies, people who live in rural communities, people who have orange skin, etc. To make it a conditional claim, we have to then say that the member of the group have a certain characteristic: "People who like anchovies also like olives".

In this question, we get no necessary condition, as we are not told that the people who are in those groups all have certain characteristics. Instead, we get that the members of the group (participating in local politics) may also belong to other groups. We don't get told anything about ALL of the people in local politics, or ALL of the selfish people, or ALL of the genuinely interested people. It's just that one group has members that may also be in other groups. In fact, we don't know that those two subgroups make up all of the people involved in local politics. That group includes the second two groups, but maybe it also includes people who are just bored and looking for something to do? People trying to meet new friends? People who were ordered to get involved as a condition of their community service? "A includes some B" is not conditional, but is rather a statement involving the closely related concept of Formal Logic.

In your second example, though, we definitely have a conditional relationship. We know that IF you are a small country or IF you are a country in the southern hemisphere THEN you are not on the security council. The members of those two groups all have a certain characteristic. Diagram that, think about the contrapositive, and you'll be in good shape.

I hope that illustration of the difference between those types of statements helps!
Hi Adam - thank you, this is very helpful. I have one more question, it would be incorrect to diagram this right:
local politics :some: genuinely interested & selfish opportunists?

Because doesn't this that SOME people in local politics are both genuinely interested & selfish opportunists? My main source of confusion was why it could not be written as a conjunctive conditional.
 Adam Tyson
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#38604
You could, although it would be better to diagram it as two separate statements:

Local Politics :some: Genuinely Interested

Local Politics :some: Selfish Opportunist

To diagram it the way you did would suggest that some people are both of those things, when what you are trying to say is that some are in one group and some are in the other. There is no indication that anyone involved in local politics is both genuinely interested and a selfish opportunist.

Conjunctive conditionals, or what we simply call multi-conditional statements, indicate that when the sufficient condition occurs, the necessary conditions BOTH occur (if you are looking at an AND statement) or that AT LEAST ONE occurs (if you are looking at an OR statement). Here, though, we don't need either for any given case, so this isn't truly conditional at all. Again, this is Formal Logic, not Conditional Reasoning, and while the diagrams bear some resemblance to each other, they require different approaches, often giving consideration to what you know, and do not know, about the numbers of the various groups being compared.
 hbaezh
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#86249
As other students have mentioned I was also confused by the presence of both 'those who and people who' is the stimulus. I understand why the A is the correct answer but I am still confused on when I can determine that 'those who and people who' is NOT showing a conditional relationship.

What is the logical explanation of WHEN to read 'those tho and people who' and translate it to SOME? and how can I make sure I am translating to SOME in the correct situation or when to read 'those who and people who' sufficient conditions?

Would it be ONLY when a necessary condition is present to read them as sufficient? and then when they are present without a necessary condition to read them as SOME?

Thanks in advance!
 Robert Carroll
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#86910
hbaezh,

Indicators are helpful, but cannot be mechanically employed. Let's see why, in this case, we have a pair of "some" statements and not a conditional.

Check out the following example:

"Those who succeed in medical school are highly motivated."

This is intending to give me something which characterizes ALL people who succeed in medical school.

Compare:

"Those who succeed in medical school include people who won't succeed in medical practice."

This is not intending to characterize all people succeeding in medical school, but is satisfied if at least some people succeed in medical school but not in medical practice.

Compare what it would take to validate each statement: the first is true only if all people who succeed in medical school have a certain quality, whereas the second is true even if only some people combine success in medical school with lack of success in medical practice.

When we have "those who" or "people who", the key is to ask whether the author is trying to characterize an entire group or merely part of a group. If the former, it's a conditional; if not, it's a "some" statement.

The stimulus is trying only to say that some who participate in local politics have a certain quality. So we have "some" statements.

Any conditional must of course involve a necessary condition. A conditional is a universal statement - it says that all things in a group must have a certain quality. The nature of the group is the sufficient condition. The quality that all members of that group must have is the necessary condition. Because the author is not saying that everyone in a group MUST have something true (only that some do), there is not a conditional present in the first sentence of the stimulus.

Robert Carroll

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