请教：狒狒8

The stable functioning of a society depends upon the relatively long-term stability of the goals of its citizens. This is clear from the fact that unless the majority of individuals have a predictable and enduring set of aspirations, it will be impossible for a legislature to craft laws that will augment the satisfaction of the citizenry, and it should be obvious that a society is stable only if its laws tend to increase the happiness of its citizens.

The claim that a society is stable only if its laws tend to increase the happiness of its citizens plays which one of the following roles in the argument?

(A) It is the conclusion of the argument.

(B) It helps to support the conclusion of the argument.

(C) It is a claim that must be refuted if the conclusion is to be established.

(D) It is a consequence of the argument.

(E) It is used to illustrate the general principle that the argument presupposes.

感觉stable of a society 只跟goals of citizens相关，也就是与aspiration相关，如果没有aspiration，没有goal，制定出increase the happiness of the citizens的law也没有用啊？题干中还用了only if 来表达。

请指教？

题目问的是这个说法society is stable only if its laws tend to increase the happiness of its citizens 在这段话的作用是什么？

楼主的问题是推导什么呢？

only if 有什么问题？

The stable functioning of a society depends upon the relatively long-term stability of the goals of its citizens.

这是个充分条件，relatively long-term stability of the goals of its citizens --〉stable，

a society is stable only if its laws tend to increase the happiness of its citizens.

这是个必要条件，stable --〉increase the happiness of its citizens。

记得以前似乎我们做数学证明题的时候，必要条件都是拿来证明充分的。

证明充分必要条件题，实际上是证明两次充分，A--〉B且B--〉A，所以A，B互为充要条件。

所以本题中的第一句话作为结论更为合适，最后一句话更适合拿来作为证明的条件更为合适。

不知道理解得有没有问题，欢迎大家指正。