Cannot be true and Causation questions

[akalsi]

Hi,

I have a question regarding how to best tackle Cannot be true questions that involve Causality.

I understand that with conditional relationships what cannot be true (and what we should be looking for in an answer choice) is where the sufficient condition occurs but the necessary condition does not occur.

It's mentioned that Cannot be true questions can be thought of as reverse weaken questions. I get how that relates in terms of looking at it from the two types of families, but I'm having a hard time understanding how this relates with causation. In weaken questions there are 5 ways we can Weaken a causal conclusion. If we are to look at Cannot be true questions as reverse Weaken questions, in terms of causality, are we looking for 4 answer choices that do what a Strengthen causal question would do and 1 answer choice that is doing what a Weaken causal question would do?

I don't know if that's the best way to understand the relationship between cannot be true questions and causality, but an explanation on how to understand what we should be looking for in an answer choice would be helpful (similar to what we know with conditional statements).

Thank you in advance!

[Emily Haney-Caron]

HI akalsi,

Thanks for the question. I'm glad you're really taking the time to think through the material you're reading; great work!

When thinking of Cannot Be True as reverse Weaken questions, you aren't trying to reverse the strategies you'd use with Weaken questions and apply them to Cannot Be True. Instead, this is just to help you think through how these questions function. So, instead, with these questions when you have causal reasoning, you're looking for 4 answers that could be true, and one answer that cannot be. Really, the main rule here, you already stated: find the answer where the sufficient condition occurs and the necessary condition does not occur. That's it! Sounds easier than it is in practice, but that's the method you'll want to use and practice applying. Let us know if there's a particular question you want to talk through to get a better sense of how this works.

[akalsi]

I'm still a bit confused. I understand how Cannot be true questions work for Conditional relationships, but still having some trouble with Causal relationships.

If I understand what your saying to me is that in a causal relationship, the author assumes that A always causes B. So similar to a conditional relationship, there are 4 possibilities:

1) A B
2) not A not B
3) not A B
4) A not B

So my understanding is, that contrary to conditional relationship, where the only possibility that cannot be true is A not B, in a causal relationship there are two possibilities that cannot be true: not A B and A not B. So we should be looking for an instance where either of those two possibilities show up in an answer choice and that would be the correct answer for a cannot be true question.

Please let me know if I'm on the right track with this.

Thanks in advance!

[Claire Horan]

Hi Akalsi,

You've come to the right conclusion. On the LSAT, causation means that the cause does not occur without the effect, and the effect does not occur without the cause. It's worth noting that this is much stricter than what we mean in everyday life when we say something "causes" or "is a cause of" something else.

Great question!

Claire