句子分析如下
It是形式主语 is是系动词, indeed是状语, in the highest degree是状语 likely 是表语that language is an instrument是主语从句作真主语 originally put to uses lower than the conceptual plane 是过去分词短语作定语and that thought arises as a refined interpretation of the content.是并列的主语从句。
句子意思:事实上,语言可能原本是一种用来使用的程度低于概念层面的工具,而思维是对内容的精炼理解。