Actions and Consequences

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 75
Joined: Thu Oct 23, 2008 4:25 am
Thanked: 6 times
GMAT Score:620

Actions and Consequences

by madhukumar_v » Fri Apr 16, 2010 2:02 pm
9. Every action has consequences and among the consequences of any action are other actions. And knowing whether an action is good requires knowing whether its consequences are good, but we cannot know the future, so good actions are impossible.
Which of the following is an assumption on which the argument depends?

(A) Some actions have only other actions as consequences.
(B) We can know that past actions were good.
(C) To know that an action is good requires knowing that refraining from performing it is bad.
(D) Only actions can be the consequences of other actions.
(E) For an action to be good we must be able to know that it is good.

OA: E

Can any one please explain why OA is such, prefer negation technique.
Source: — Critical Reasoning |

GMAT Instructor
Posts: 357
Joined: Wed Aug 12, 2009 8:31 pm
Thanked: 128 times
Followed by:7 members

by grockit_andrea » Fri Apr 16, 2010 2:23 pm
The argument's conclusion is that "good actions are impossible," and the main evidence in support of that is the idea that, since we can't really foresee the consequences of an action, we can't tell if it's good or not. There is a logical leap here between knowing that an action is good, and the action itself being good. If E weren't true, and an action could be good without one knowing that it is good, then the fact that consequences can't be completely foreseen wouldn't keep an action from being good.

This is a confusing argument, I think, just because the same terms are repeated over and over. Basically, negating the assumption comes down to saying, "Who says that you have to know that an action is good in order for it to be good?"
Andrea A.
Grockit Tutor
https://www.grockit.com

Senior | Next Rank: 100 Posts
Posts: 75
Joined: Thu Oct 23, 2008 4:25 am
Thanked: 6 times
GMAT Score:620

by madhukumar_v » Fri Apr 16, 2010 4:58 pm
I didnt see that difference between knowing that an action is good, and the action itself being good

Thanks for the explanation.

Master | Next Rank: 500 Posts
Posts: 379
Joined: Wed Apr 07, 2010 12:53 am
Location: Chennai,India
Thanked: 3 times

by paddle_sweep » Sat Apr 17, 2010 11:27 pm
I am not clear as to why 'E' is the answer. Could you explain it again please?