72) Some philosophers argue that rights exist only within a social contract, as part of an exchange of duties and entitlements.　　句子分析：　　第一、句子可以拆分为三段：Some philosophers argue / that rights exist only within a social contract, / as part of an exchange of duties and entitlements.第二、句子的结构：　　1)主干结构是主从复合句：Some philosophers argue that...　　2)that引导的是宾语从句　　3)as part of...是宾语从句中的rights的主语补足语。　　第三、词的处理：　　argue 论证　　a social contract 社会契约　　as part of 作为(是)……的一部分　　entitlements 利益，权利　　完整的译文：　　72)有些哲学家论证说，权利只存在社会契约中，是责任与利益相交换的一部分。　　

73) It leads the discussion to extremes at the outset: it invites you to think that animals should be treated either with the consideration humans extend to other humans, or with no consideration at all.　　句子分析：　　第一、句子可以拆分为三段：It leads the discussion to extremes at the outset: / it invites you to think that animals should be treated / either with the consideration humans extend to other humans, or with no consideration at all.　　第二、句子的结构是：　　1)it invites you to think that...后面是宾语从句。　　2) animals should be treated either with..., or with...要么……要么……，是表示选择的方式状语。　　3)the consideration后面的humans extend to other humans是定语。　　第三、词的处理：　　leads ...to extremes 引向极端　　at the outset 从一开始　　invites you to think 使人们认为　　consideration 关切，体谅　　humans extend to other humans 人对待人完整的译文：　　73)这种说法从一开始就将讨论引向两个极端，它使人们认为应这样对待动物：要么像对人类自身一样关切体谅，要么完全冷漠无情。　
　

74) Arguing from the view that humans are different from animals in every relevant respect, extremists of this kind think that animals lie outside the area of moral choice.　　句子分析：　　第一、句子可以拆分为三段：Arguing from the view that humans are different from animals in every relevant respect, / extremists of this kind think / that animals lie outside the area of moral choice.　　第二、句子的结构：　　1)主干结构是现在分词短语状语，主语+谓语+宾语从句。Arguing from...现在分词短语作状语。　　2) the view和后面的从句that...是同位语关系　　3) that...引导宾语从句。　　第三、词的处理：　　Arguing from the view 从……观点看，持……观点　　different from... 与……不同　　in every relevant respect 在各相关方面　　extremists 极端主义者，持极端观点的人　　lie outside the area of moral choice 不在道德问题范围，与道德取舍无关完整的译文：　　74)这类人持极端看法，认为人与动物在各相关方面都不相同，对待动物无须考虑道德问题。