## A cause B. so C can't also cause B?

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### A cause B. so C can't also cause B?

If we have...
A Causes B.
and we need to weaken this and the answer choice says:
C causes B.

Is this answer choice right or wrong?

My sense is that it doesn't matter if A causes B. C can also cause C. So it doesn't weaken. HOWEVER, it could also weaken by showing that B has another cause.

Hotguy

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Joined: Mon Sep 16, 2013 12:33 am

### Re: A cause B. so C can't also cause B?

A Causes B.
and we need to weaken this and the answer choice says:
C causes B.

Is this answer choice right or wrong?

My sense is that it doesn't matter if A causes B. C can also cause C. So it doesn't weaken. HOWEVER, it could also weaken by showing that B has another cause.

It weakens.

Pancakes12

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### Re: A cause B. so C can't also cause B?

Yes, both A and C could possibly both cause B. So you are right in thinking that it doesn't destroy the argument. But it does weaken it because it opens up another possibility. The correct answer to a weaken question only has to weaken ever so slightly.

Edited for grammar.

Clearly

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### Re: A cause B. so C can't also cause B?

Alternative cause weakens.

bp shinners

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### Re: A cause B. so C can't also cause B?

jlb251 wrote:So you are right in thinking that it doesn't destroy the argument. But it does weaken it because it opens up another possibility. The correct answer to a weaken question only has to weaken ever so slightly.

This is an important note - you have to weaken the argument, not destroy the argument. A lot of people get hung up on that.

But to the original question - as others have said, noting an alternative cause will weaken a causal conclusion.