Ideas are only intelligible within the particular circumstances that give rise to them

Discourses (written and spoken communications) come in many sizes and forms and some overlap, some have more power than others. People subsequently behave around these discourse believing them
to be knowledge imparted by our betters. 

Undergirded by these discourse believing them to be epistemologically  valid we trail in their wake.

But let us pause to get epistemology under our belt - What are the necessary and sufficient conditions of knowledge? What are its sources? What is its structure, and what are its limits? As the study of justified belief, epistemology aims to answer questions such as: How we are to understand the concept of justification? What makes justified beliefs justified? Is justification internal or external to one's own mind? Understood more broadly, epistemology is about issues having to do with the creation and dissemination of knowledge in particular areas of inquiry. 

 Discourses arise out of epistemology - and people invoking principles. But these discourse have an unnerving portability - ideas, principles, the point of the argument and ideas are only intelligible within the particular circumstances that give rise to them.