I disagree with "common sense." In my experience, when questioning people about what they mean by common sense, I find that they usually mean "general principles that seem like obviously correct to me." And that doesn't even guarantee that they are correct.
I was just wondering. Human minds are messed up in 1001 ways, but are there a few rational principles that most people already have down? Of course, the answers to this question are probably so extremely obvious that I haven't even considered them. But I ask all the same.