These ideas might be true/false, but people just assume them. An example would be: you need some kind of money/currency for a civilization to be functional.
There are quite a few terms; I originally phrased my question What is an “unarticulated background”? to as for other terms. Here are the terms I've discovered so far:
- "tacit knowledge"
- "unarticulated background"
- "form of life"
- "social fact"/"taken-for-grantedness"
- "collective unconscious"/"collective representation"
I particularly suggest looking at social fact, it comes from the sociology of knowledge, which began to exist in its current form after Berger and Luckmann published The Social Construction of Reality.
These could be referred to variously as common knowledge, common sense, assumptions, conventional wisdom and various other terms, depending on the correctness or otherwise that you are ascribing/insinuating of them.
For instance, if you wish to imply that something without known proof is true, you may choose to state that "it is common knowledge that...", but to imply that you believe an assumption is false you may choose "it is conventional wisdom that ..." . All such arguments encourage the listener to proceed without explicit proof, and should in such a case be carefully scrutinised.
Whereas the word "faith" carries a positive conotation and the word "prejudice" carries a negative conotation, both represent the same fundamental concept.
Common sense is the collection of prejudices acquired by age eighteen.
-- Albert Einstein