The ten commandments is a debate that many people get into. I believe that they shouldn't be posted in front of public buildings. Yes, the commandments are morally based, but we have to think about the whole separation of church and state thing. There would be no problem with posting the commandments if they didn't seem like they were trying to enforce religion.
First, there is the commandment which states, “Thou shalt not have any god before me.” There is no way anyone will be convinced the Ten Commandments are there for a secular purpose. It blatantly supports a religious view, as you will see in t