Social science is that branch of intellectual enquiry which seeks to study humans and their endeavors in the same reasoned, orderly, systematic, and dispassioned manner that natural scientists use for the study of natural phenomena.

楠楠自语

Step one：谓语动词is, seeks, use

Step two: 连接词which, that

句子主干：Social science is that branch of intellectual enquiry。

其中which引导定语从句修饰intellectual enquiry， which引导的定语从句较长，翻译时可以重复先行词，独立成句，放在所修饰名词的后面；

在介词短语中又嵌套第二个定语从句that natural scientists use for...，that引导的定语从句较短，则翻译时可以放在manner之前，翻译为“…的方式”

【串联成句】

社会科学是知识探索的一个分支，它力图像自然科学家研究自然现象那样，用理性的、有序的、系统的和冷静的方式研究人类及其行为。