Culture as a vacum.

This post is quite short. I hope only to convey a short expression.

Culture, those ideas, values, beliefs and behaviours of a community or nation act as a vacum for real knowledge and thought.
What i mean to say is that within our culture the knowledge that we have is more or less self propagated. Ideas and values held as correct are culturally related e.g. capitalism, monogamy, democracy, freedom, abortion, vegetarianism or what have you...
So any comment that has the advocacy of the "culture" will be positively reinforced.
Radical ideas that are not within the confines of that culture are more or less disregarded, like catholics thinking about allowing abortion, capitalism thinking about communism...

In many ways culture is an assumption. Our metal process, our rational thought quite often is underpinned and justified by those assumptions.

sorry i'm being abstract, it'd take a while to articulate the very examples that I myself am subject to, and thus find them difficult to question.