#15- Humans are supposedly rational: in other words, they

[Nina]

Great help! Thank you so much!

[JocelynL]

With answer choice (B), there is no evidence that the author makes this assumption. Even if humans were not aware of the irrational nature of their acts, the conclusion would not be any weaker.

In flaw questions, when we identify the flaw, is it safe to say we are simultaneously weakening the conclusion? So flaw and weaken could be very related?

[Adam Tyson]

Very much so, JocelynL! I think of it this way - a Flaw answer points out a problem with the argument, while a Weaken answer takes advantage of that problem. It's like the difference between someone telling you that you dropped your wallet and that person picking it up and walking away with it. The former is just a description, while the latter is an active attack. There can be no weakening of an argument if there is no flaw to take advantage of!