"Common sense" is what you invoke when you cannot support your beliefs with either "real arguments" or "real data."
Common sense is the noise that comes out of you when all you've got is the vague sense that you must be right--somehow?--but even *you* don't know why you think that.
Common sense is a slogan for shutting down arguments without having to know or prove anything.
Version) @doctorambient Agreed. Imo "common sense" and "intuition" are synonymous and both are usually wrong.
@TopNotchSwords True!
English has a lot of expressions for trying to make bullshit sound like reason.
@doctorambient on the other hand yours can be said to be an argument of the privileged academic, who through vocation and witty sarcasm, tries to defang any common sense upfront.
Common sense is simply knowing what has been proven before.
Common sense is quite handy imho for the everyday person, who does not want to delve into DOI to back up every word in a conversation :)
And common sense is ethereal. It is not in the eye of the beholder, that is opinion, bias, dogma, myopia, ideology, etc.
I'd argue that most people do believe that common sense refers to that which has been "proven before" but it doesn't. It's usually just a term for the mishmash of ideas that most of us carry around in our heads, some of which is true and much of which isn't. It's usually a thought stopping cliche.
Maybe you are privileged enough to live in a world where people only assert true statements, but I constantly hear people call all sorts of falsehoods common sense.
¯\_(ツ)_/¯
@doctorambient
The issue with 'common sense' is that there's actually no 'common' in it at all. It's the incorrect belief that what's 'normal ' for you should be 'normal' for everyone else. Reality check: It's not! People are different, contexts are different. Your normal can and will be different from other people's normal.
@onepict
I agree, that's a very good point!
And I think it gets at one of the two core problems. A lot of people use common sense as a way to stop an argument by assuming that the majority of people around them will just agree automatically with their point of view. That is the common part.
There is also the "sense" part: talking about "common sense" often emerges at the point in a disagreement where one specifically needs to be able to challenge the other person's argument. And they can't.
Yeah, and then there's the implicit 'you're silly if you don't agree with me' in the use of 'common sense'. Which doesn't exactly help building a fair argument or discussion... 
(Funny I noticed your post here. Just last week the use of 'common sense' came up at work. In HR in an international organisation. Really, there is no 'common sense' in international HR, countries, cultures and laws are different!)