LSAT Discussion Forum

Hi Mo,

It looks like you're misreading what (C) is saying: if all dishonest people are rich farmers (H Rf), then we know that if you're not a rich farmer, you're honest (Rf H), but it still leaves open the possibility that some rich farmers are honest. (C) only gives us information about the "dishonest" group, not the "rich farmer group".

(A) works because its contrapositive, Pf Hf, when translated from "not poor" to "rich" and "not honest" to "dishonest," becomes Rich Farmers Dishonest Farmers, which is exactly what the conclusion states.

Hope this helps!

This question I think I have an understanding but of it now but I want to see if I'm correct in my thinking

R ----->~P missing link ~H -------> D

a) contrapositive of the link
b) allows for rich people to still be honest
c) it talks about dishonest people, so we know nothing about the opposite (honest), meaning you could still be rich?
d) rich can still be honest
e) irrelevant

Hi Mo,

It looks like you're correct about the answer choices, although, I'm not sure about the linkage diagram you made. Here's how I would diagram the stimulus:

R = P, and P = R. H = D, and D = H. It's helpful to put this up, so that when we get to actual conditionals, we can remember what each term means, both positive and negative.

So we only have one conditional, plus a conclusion that seems to be drawn from a Mistaken Negation of that conditional.

Conditional: Pf Hf (Rf Df)

Contrapositive: Hf Pf (Df Rf)

Now we have to justify the claim that all rich farmers are dishonest (Rf D). Looking at the above diagram, making all honest farmers poor will give us, via the contrapositive, that all rich farmers are dishonest:

Hf Pf,

with the contrapositive

Rf D

(A) gives us that, which makes it the correct answer choice. Hope this helps!

This response to be the only one that addresses the biconditionality, which adds greatly to understanding how to arrive at the correct answer. Perhaps it needs to be listed at the beginning of the thread?

Nikki Siclunov wrote:Hi angle23,

Your understanding of the stimulus is correct. Since you are either rich or poor, and either honest or dishonest, the logical opposite of "poor" (i.e. "not poor") is logically equivalent to being "rich." The same applies to being honest and dishonest. Hence:

Premise: Poor Honest

Conclusion: Poor Honest

You are correct in your observation that the conclusion is a Mistaken Negation of the premise. It is incorrect to say, however, that answer choice (A) is a Mistaken Reversal of that premise. The Mistaken Reversal (or Negation) are errors in inference-making. In other words, they are fallacious only as deductions from the original condition. The conclusion is a Mistaken Negation, because conclusions are axiomatically inferred from the evidence presented. Answer choice (A), by contrast, is not an inference from any premise: it is merely a statement we are instructed to assume as true. So, if every honest farmer is indeed poor, we can diagram this as:

Answer choice (A): Honest Poor

As you may notice, this is the contrapositive of the conclusion. The two are identical in meaning, which is why the conclusion is properly drawn if we assume that answer choice (A) is true. On a side note, when combined with the premise, answer choice (A) + Premise produce a bi-conditional statement in the following form:

Honest Poor

Let me know if this helps!

Thanks for the great clarifications thus far! This question does not seem to be assuming anything. The answer choice is simply a contrapositive of the conclusion. Or am I missing something?

In LSAT terms, when faced with a conditional conclusion, the author is assuming the contrapositive is also true (unless he explicitly says so, in which case it is no longer an assumption but a premise). As with any assumption, if we were to negate this answer it would destroy the argument, proving it to be correct.

While we might see conditional statements and contrapositives as being the same thing, at least for testing purposes accepting the truth of one assumes the truth of the other, so it is fair game for an assumption question. You should expect one or two questions that do exactly that, BLG!

So we are trying to link the premise to the conclusion. Since the contrapositive of answer A links the conclusion and proves it due to it being a justify question? I answered C for this question but looking back at it, it is not correct because it uses the terminology "everyone" and it does not provide a link to the conclusion through its contrapositive? Sorry, this was a difficult question.

Nicholas,

Every answer either says "everyone" or can be rephrased as a statement involving "everyone" straightforwardly. Thus, that word cannot be a problem with any answer. The problem is that answer choice (C) does not show that every rich farmer is dishonest - to think so is to make the Mistaken Reversal. As you pointed out, the contrapositive of answer choice (A) proves the conclusion, making it the right answer.

Robert Carroll

I got this questions right, but only by process of elimination. I took the contrapositive of the conclusion, and saw that (A) was closest to it.

I had a question regarding the placement of the word "farmer" in the necessary and sufficient condition.

The conclusion is: Rich Farmer Dishonest.

I took the contrapositive to be: Honest Poor Farmer.

Yet (A) said the contrapositive is Honest Farmer Poor.

In the real world, I can see why that makes sense (because the premises are specific to farmers, not the general population). But how do you justify logically why the word "farmer" does not "switch" from the sufficient to the necessary condition?

"Farmer" is actually implicit in both conditions, ikim10. If a farmer is rich, then that farmer is dishonest, so if that farmer is honest, that farmer is poor. BOTH conditions are solely about famers.

Another way to think about this is to treat "farmer" as limiting the scope of the conditional rule. It's like saying "here is a rule that applies to farmers: if they are rich, they are dishonest."