英语翻译We will use this picture as a backdrop for a picture of

英语翻译
We will use this picture as a backdrop for a picture of Immanuel Kant—the greatest philosopher of all time—a man whose philosophy formed the basis of that of many of our founding forefathers who framed the Constitution.

首先,面对长句,要先找到句子的主干.面对这种有插入句的长句,找主干的第一步就是暂时先忽略两个破折号中间的句子.那么这个长句剩下的内容就是：
We will use this picture as a backdrop for a picture of Immanuel Kant,a man whose philosophy formed the basis of that of many of our founding forefathers who framed the Constitution.-此句标记为 句1.
那么 句 1 的主干是什么呢?句 1 中,逗号后面的一长串内容其实是由whose 引导用于修饰 "a man" 的定语从句.也就是说,逗号后面的内容不属于主句,只是对Kant这个人的补充性描述.于是,我们就得到了主句：
We will use this picture as a backdrop for a picture of Immanuel Kant.此句标记为 句 2.
找到的主干 句 2,其实就是一个比较简单的单句了,此处可译为：我们要用这幅图片作为 艾曼努尔.康德画像的背景.原句剩余的部分还有：
a man whose philosophy formed the basis of that of many of our founding forefathers who framed the Constitution - 此部分标记为 part A
the greatest philosopher of all time - 此部分标记为 part B
先翻简单的.
Part B 可以翻译为,“史上最伟大的哲学家”.
剩下的是看上去结构比较复杂的 part A.这里说看上去复杂,主要是因为楼主在提问中提到的 "of that of many" 这个地方比较有迷惑性,但是如果把 "that" 指代的内容搞清楚,其实也没有多复杂了."that" 所指的应该是句中在它之前出现过的sth.,是个名词,而前面出现过的名词也就这几个"a man","philosophy","the basis",肯定不会是"the basis",否则该结构就变成"the basis of the basis",不通,同理"the basis of the man",也解释不通；于是只剩下"philosophy",带入该结构,我们的 part A 就变成了:
a man whose philosophy formed the basis of (the) philosophy of many of our founding forefathers who framed the Constitution.-此部分标记为 part B+.
我们再来看 part B+ 的结构分析.既然是一个由whose引导的定语从句,就先把中心语 "a man" 忽略掉,直接看从句部分,同时根据其内容做一个顺序上的修改,就变成了：
Kant's philosophy formed the basis of (the) philosophy of many of our founding forefathers who framed the Constitution.- 此句标记为 句 3.
很烦人的一个句子,有3个 of 跟一个 who.依然按照分析主干的方法,可以把 句 3 分解成一下的部分：
Kant's philosophy formed the basis of philosophy - (whose philosophy?)
- many of our founding forefathers' philosophy -(what did they do?)
- they framed the Constitutuion.
好了.现在原来看似复杂的长句已经被彻底分解了.
整个长句的翻译如下：
我们要用这幅图片作为 艾曼努尔.康德画像的背景——康德是世上最伟大的哲学家,他的研究成果为我们的开国前辈们的哲学认识奠定了理论基础,而正是这些前辈们制定了我国的宪法草案.