逻辑大全 test D-15

virnnie

Susan: Those who oppose experimentation on animals do not properly value the preservation of human life. Although animal suffering is unfortunate, it is justifiable if it can lead to cures for human ailments.
Melvin: But much animal experimentation involves testing of ordinary consumer products such as soaps, dyes, and cosmetics.
Susan: These experiments are justifiable on the same grounds, since cleanliness, convenience, and beauty are worthwhile human values deserving of support.
Which of the following is the best statement of the logical flaw in Susan’s argument?
(A) Her claim that animal experimentation is justifiable if it supports human values contradicts her claim that such experimentation is justifiable only if it leads to cures for human ailments.
(B) She places a higher value on human cleanliness, convenience, and beauty than she does on the preservation of animal life.
(C) She uses the word “value” in two different senses.
(D) She assumes that all ordinary consumer products aid in the preservation of human life.
(E) She fails to show how mere support for human values actually preserves human lives.

并不能理解A项中only if的出处。而且这道题的flaw到底在什么地方？个人觉得Susan只是很牵强的补全了自己的前提。（在讨论链接中没有找到此题）求NN解答！

alzn2765

首先，我觉得这题原题出的时候可能在题干里落了一个“Only”，也就是it is justifiable only if it can lead to cures for human ailments，否则逻辑上讲不通。

如果把这个only加上去，则：

题干：
Susan: experimentation on animals is justifiable---->it can lead to cures for human ailments

Susan: it supports human values (such as  cleanliness, convenience, and beauty)---->animal experimentation is justifiable

而to cures for human ailments 不等于 it supports human values (such as  cleanliness, convenience, and beauty)

在必要条件没有满足的情况下，充分条件不可能发生。

说白了，Susan说在动物身上实验必须是为了治病救人，但Melvin反驳说制造香皂盒化妆品显然不算是治病救人啊！Susan又说为了清洁，方便和美丽等人类价值，这些实验是值得的。明显Susan前后矛盾了啊。

virnnie

alzn2765 发表于 2015-9-29 21:20
首先，我觉得这题原题出的时候可能在题干里落了一个“Only”，也就是it is justifiable only if it can lea ...

嗯。如果题干有only的话的确很符合A。

我当时选的C。可能觉得读起来，Susan刚开始觉得human value是在生命的延续上面（就是要治病），而后来她又补充说那些化妆品啊什么的也是值得支持的human value。我不知道这样理解对不对？还是说最开始Susan说的话就没有提到human value，所以也就不存在有两种理解？

alzn2765

virnnie 发表于 2015-9-29 21:37
嗯。如果题干有only的话的确很符合A。

我当时选的C。可能觉得读起来，Susan刚开始觉得human value是在生 ...

Susan的第一句话根本没出现human value，那个句子里唯一的一个value是动词。

virnnie

alzn2765 发表于 2015-9-29 21:41
Susan的第一句话根本没出现human value，那个句子里唯一的一个value是动词。

好的，谢谢！