the pieces of reality that are to be learned ,whether they a

the pieces of reality that are to be learned ,whether they are the alphabet or an understanding of
government,have been limited by the subjects being taught.

句子主干是
the pieces have been limited
那些我们要去学习的真相,不论是那些非常基础的ABC还是对事物道理的理解,都被限定于所被传授的事物本身.
意思就是,无论你学的东西简单或是复杂,都被限定于你的老师怎么教.
比如教你数学,现代数学都用十进制,那你对数学的理解就是建立在十进制之上的,被限定于十进制了.例子可能不恰当,大概是这个意思吧.

我也是这个答案