The sad truth is that there will never be total world peace. The simple reason for this is that there is always conflict between the concepts of groups of people having the freedom to set their own moral code but at the same time have other groups with different moral codes to interact and not offend each other somehow. The simple concept that my moral code says that I want to have certain beliefs as well as a belief that a given behavior is wrong and not only do I not want to practice that behavior, but I feel entitled to not have to deal with others who do. If you think