This is from the The Stanford Encyclopedia of Philosophy"

When “morality” is used in this descriptive way, moralities can differ from each other in their content and in the foundation that members of the society claim their morality to have. A society might have a morality that is primarily concerned with practices not related to other persons, e.g., which days must be devoted to certain rituals, and might claim that their morality, which is concerned primarily with ritual, is based on the commands of God. Or a society might have a morality that is concerned primarily with sexual practices, and claim that their morality, which has this concern, is based on human nature. Or a society might regard morality as being concerned primarily with practices that minimize the harms that people suffer and claim that their morality, which has this concern, is based on reason. Many societies have moralities that are concerned with all of the above and that are claimed to have all three of the above foundations. But, in this sense of “morality,” regardless of its content, or the justification that those who accept the morality claim for it, the only universal features that all moralities have is that they are put forward by a society and they provide a guide for the behavior of the people in that society. In this sense of “morality,” morality might allow slavery or might allow some people with one skin color to behave in ways that those with a different skin color are not allowed to behave. In this sense of “morality,” it is not even essential that morality incorporate impartiality with regard to all moral agents, those people whose behavior is subject to moral judgments, or that it be universalizable in any significant way.

So basically Tom, your premise that morality is this universal truth differs from its basic definition. We could easily just be debating symantics here but I think it points to this underlying difference in the way people think. If one embraces the concept that their morality is somehow a part of our basic being (which implies some outside force putting it there) it puts them at odds with the cold hard fact that morality seems to have different definitions within different cultures. I would assume that it is well within your morals to crush a bug beneath your feet and yet within a Buddhist culture that could be considered an immoral act.

It seems to me that the only universal truths we seem to find are those relating to quality and quantity of life, basic survival skills. All cultures since the beginning of time have found that restrictions on certain sexual activities, murder, and stealing have resulted in longer lifespans and greater quality of life.