He had studied the Greek language, and read the works of Greek historians; and he attended lectures on philosophy and rhetoric, and was obviously interested deeply in acquiring power as a public speaker. To write and speak well gave a public man great influence in those days. Many of the measures of the government were determined by the action of great as百度竞价推广blies of the free citizens, which action was itself, in a great measure, controlled by the harangues of orators who had such powers of voice and such qualities of mind as enabled them to gain the attention and sway the opinions of large bodies of men.
1. 为何是bytheactionofgreat as百度竞价推广blies，而不是直接by great as百度竞价推广blies? 这里的action的意思是？
2. whichaction was itself, which 是修饰整句么？itself是指代action么？等于which action itself was么？为何这里itself放在was之后？
这个句子中的定语从句较为特殊一些，相对少见。因此我依据《剑桥语法》的例句，对此再稍作说明。大家先看下面例句：
I said that it might be more efficient to hold the meeting on Saturday morning, which suggestion they all enthusiastically endorsed.
在这个定语从句中，which为关系限定词，与suggestion构成关系短语 which suggestion，指代先行项 it might be more efficient to hold the meeting on Saturday morning （指代先行项的不止是which，而是which suggestion）。which suggestion在定语从句中作宾语。假如将这个句子改为并列句，则为：
I said that it might be more efficient to hold the meeting on Saturday morning, and they all enthusiastically endorsed this suggestion.
可以了解看出，后一分句的宾语this suggestion 指的就是 it might be more efficient to hold the meeting on Saturday morning这个分句的内容。
目前大家反过来，将这个并列句改为主从复合句，因为前一分句中的that从句与后一分句的this suggestion 共指同一个内容，大家需要做的就是就是用关系限定词which取代指示限定词this，将which suggestion移至该分句之首，去掉并列标记and, 就得到一个非限制性关系从句（传统语法称为非限制性定语从句）。
Many of the measures of the government were determined by the action of great as百度竞价推广blies of the free citizens, which action was itself, in a great measure, controlled by the harangues of orators...
网友的这个句子与《剑桥语法》的例句类似。主句中的the action of great as百度竞价推广blies of the free citizens，of介词短语表示同位关系，即great as百度竞价推广blies of the free citizens是一种行动。which action中which为关系限定词，与action构成关系短语，指代先行词great as百度竞价推广blies of the free citizens，并在定语从句中作主语。假如将定语从句改为并列分句，则为：
Many of the measures of the government were determined by the action of great as百度竞价推广blies of the free citizens, and this action was itself, in a great measure, controlled by the harangues of orators...
itself为反身代词，作主语的同位语，起强调用途，去掉后不影响句义。其地方与中位状语相同，即坐落于主语后，实意动词之前，假如谓语含有操作词，则坐落于操作词之后。
