Weaken possible conclusion

[cxmss170]

When I read the HW 3 required reading, it said “using alternate cause is not effective to weaken a possible conclusion”, but page 59 mentioned one of the 3 ways to weaken possible causal conclusion is: raise a possible third cause that could cause both elements. ”

What’s the different between “alternate cause” and “possible 3rd cause?”

Thank you

[Claire Horan]

Hi cxmss170,

When dealing with possible or probable causation, the speaker is not claiming there is only one cause. For example, the statement that "eating too much can make you sick" does not suggest that nothing else can make you sick. Therefore, thinking of an alternate cause of the effect--such as a virus--would not weaken the statement of possible causation.

When the text says later that you can raise a "third cause that could have cause both elements," it means that you could raise a something new that could have caused both the proposed possible cause and the effect. In my example, the third cause could be "eating only junk food" because that could both cause you to eat too much (because it's tasty) and make you sick (because it's bad for you). My third cause undermines the statement that eating too much can cause you to be sick because I've explained the correlation between the two variables another way.