So what happens（主语）// is（系动词）// that we interpret the speakers in such a way（表语）// as to credit them with beliefs（目的状语,表语从句的目的状语） that are by and large true and coherent（定语从句，修饰名词beliefs）. 

备注：“by and large”在意思上相当于“on the whole”大体上，基本上

(1)by and large 总的来说，大体而言; 大体上; 大致如此

They were, by and large, a very wealthy, privileged elite.  

他们基本上是一些非常有钱有势的精英。

By and large, these people are peace-loving, law-abiding citizens.  

大体上，这些人都是热爱和平、遵纪守法的公民。

By and large, women can bear pain better than men.  

一般来说, 女人比男人更能忍受痛苦.

(2)adj. 一致的; 连贯的; 条理分明的; 清楚明白的

He has failed to work out a coherent strategy for modernising the service. 

他未能制定出一条连贯的策略来实现服务的现代化。

The President's policy is perfectly coherent.  

总统的政策环环相扣，浑然一体。

He's so calm when he answers questions in interviews. I wish I could be that coherent. 

他在面试中回答问题时非常从容镇静。我希望自己也能那样条理清晰。