同意刘老师解答

Absolute power was alien to those institutions, and so was what appeared to these vigorous conquerors as a dull and spiritless legality.

=Absolute power was alien to those institutions and what appeared to these vigorous conquerors as a dull and spiritless legality was also alien to those institutions

So +系动词+主语的倒装结构，主语为what 引导的名词性从句（即主语从句）

So was+what主语从句

(1)be alien to 与…相异；违反…,格格不入的；不相容的

The terms in which I speak must be alien to you: but they will become known.  

我的措辞一定与你的大相径庭,但这些话将人人皆知.

Such an attitude is alien to most businessmen.  

大多数商界人士都会对这样的态度感到陌生。

(2)institutions  n.机构; 惯例，制度，规定，建立; 社会事业机构; 名人，名物;

(3)conqueror  n.征服者;占领者

(4)vigorous  adj.  有力的; 精力充沛的; 充满活力的; 朝气蓬勃的;

(5)dull  adj.没精打采的;无生气的, 钝的; 迟钝的; 呆滞的

(4)spiritless  adj.  无精打采的; 死气沉沉; 蔫; 打不起精神来

(5)legality  n.  合法性; 墨守法规; 法律上的义务;

(6)it appear to sb that 在某人看来

Now it appears to me that he may play an important role in settling the problem.
在我看来,他可能在解决这个问题中起重要作用。

It appears to me that something has gone wrong with the election.
依我看,这次选举似乎出了毛病。

It appears to me as if he will win.
据我看,他好像能赢。

It appeared to me as if she was ill.
依我看她似乎生病了。