Human beings are guided by their limbic system. This is programmed from the day one is born. The limbic system is the decision making part of the brain. It does react to constructs introduced in the brain, such as Religious Dogma and National Laws, however, the limbic system would still work without these. Simply put, the limbic system wants to preserve the life of the person, and to seek that which causes certain neurotransmitters to be produced, while avoiding the production of other neurotransmitters. That which produces fear is avoided, that which produces elation is pursued. It's all in the lilmbic system. To be fair, people often do lean on this or that philosophy to try and help understand the underpinnings of society, the world, their souls, etc, but most philosophies actually directly reflect decisions the imbic system would be making anyway.