Weaken, strengthen,

BirdLaw818

So if I see that an answer choice weakens or strengthens just one premise, but doesnt necessarily make the argument air tight, is this still okay?

Paul Caint

I'd say so yes. So long as there isn't a better answer choice that strengthens the argument as a whole. Make sure it strengthens something directly, and you don't have to make a bunch of assumptions in order for it to strengthen.

Like:

"People say Jack jumped over the candlestick. But Jack's pants didn't have burn marks on them, therefore it is unlikely he jumped over the candlestick."

Which one of the following most weakens the argument?

1. Jack was at work today.
   ^This AC could theoretically weaken the argument. Like maybe he was at work all of today, and the candlestick was only in a public place to be jumped over during his work hours...but that's a lot of assumptions to make.

2. Jack's pants are completely fire resistant and are impervious to all fire damage.
   ^This is a better answer choice. It weakens the argument because it means that even if the premise was true, the conclusion doesn't necessarily follow.