What explanation could be needed for the fact that people naturally pursue human interests and thus relate laws and institutions to human concerns.
Morality, emerges from humanity because it exists to serve humanity. Normal human beings share the same basic survival and growth needs. We all belong to the same species and reproduce our own kind. So it should come as no surprise to anyone that we can have common interests and concerns.
Most normal human beings respond with similar feelings of compassion to like events. Our values are not all based on simple individual self-interest or egoism. There are clear cases in which our self-interest would not be served by, say, helping a suffering animal, and yet we often respond to such a situation and applaud others who do likewise. These normal compassionate responses repeatedly crop up in our literature, institutions, and laws. Thus it is clear that our morals are in large part a product of our common emotional responses, thereby allowing us to propose improvements in those morals by making appeals to the feelings of others.
The rules of logic and evidence apply equally well to everyone, and so we have a common means of arguing cases and discussing issues — a means that allows us to compare notes and come to agreement in areas as varied as science, law, and history. We can use reason and observation as a "court of appeal" when setting forth opposing viewpoints.
For these and other reasons, it should not appear strange that human beings can find common ground on the issue of moral values without having to appeal to, or even have knowledge of, a divine set of rules.
In fact, ironically, once religiously based rules are brought into any dispute, especially if there is more than one religious view present, the more the religious arguments are used the less agreement there is. This is because many religiously and theologically based values do not relate to each other or the actual human condition or the science of the world. Such values are said to come from a "higher" source. And so, when these "higher" sources disagree with each other or with human nature, there is no way to adjudicate the dispute, because the point of reference is based upon a unique faith-commitment to something invisible, not to a common range of experience.
It is theological values, then, and not human-oriented values, that are the most baseless. For, with theological values, an arbitrary leap of faith must be taken at some point. And once that arbitrary leap has been taken, all values so derived are as arbitrary as the leap of faith that made them possible.
Excerpt shamelessly taken from Fred Edwords. He sums this up better than I ever could. For other interesting topics check out: http://www.americanhumanist.org/who_we_are/about_humanism/
