People need to learn that their actions do affect other people.
So be careful what you say and do, it's not always just about you.
This could start a debate, there are several schools of thought on an issue like this.
If you truly believe that you should always speak the truth, what do you do when you know that it will hurt another person?
Do you speak your truth and the other person 'be damned' or just keep quiet? Should you 'tell it like it is' at all costs? If this means that you are deliberately hurting another human being, how can you justify that? Have you decided that it is for their own good? Should you be making that decision? Is there ever a time when 'getting physical' is okay? There are many variables on this subject.
I think the deciding factor is whether you were deliberately trying to hurt someone or if it was unintentional. If you unintentionally hurt someone an apology is in order, coupled with genuine remorse and a designer coffee.
But if the hurt was intentional an apology will not cover it. (In other words, if you picked a fight with your friend, while spewing profanity and put-downs, and landed him in the hospital..... saying you're sorry probably won't fix it.)
Whatever you say or do WILL affect others, so the first course of action is to mind your own business. It is not always about you, and it's not up to you to judge other people. You won't get away with a cavalier attitude forever, saying and doing whatever pops into your head, people will start to step away. If you find that people are staying away from you, this may be the time to take a close look at how you are affecting others in your life. Only you are responsible for your behaviour.