Philosophy, Religion, and Ethics
Over the centuries, many people have appealed to judges, kings, and religious leaders for judgments about right and wrong. Others have simply relied on their own consciences. Some moral questions seem unanswerable on a strictly natural level - that is, a level that appeals only to what people can directly observe and test. Many people have therefore appealed to the "supernatural" level - that is, a level outside the observable physical universe. Such appeals have played such an important role in moral thought that serious ethical practice requires a decision about how to handle them.
In fact, many systems of philosophy and religion have treated questions of morality over the centuries. Philosophy is the rational study of principles governing knowledge, conduct, and the nature of existence. Religion is a bit different; it is a set of beliefs and practices concerning the supernatural, conduct, and the nature of existence. Religion appeals to one or more superhuman beings as governing forces for the physical universe. Religion differs from philosophy by referring to supernatural beings and to things that must be taken on faith. Philosophy generally avoids such references. Also, religion prescribes specific moral practices, whereas philosophy does not.
Both philosophy and religion say things about moral conduct based on reason and/or faith. Systems of thought and action that appeal to the nonphysical world cannot be checked by systematic experiments. Thus, many philosophies and religions coexist, with no agreement on how to pick the "correct" one, assuming a "correct" one exists. Herein lies an unsolvable problem for ethics. Each system depends upon different ideas about human existence, which in turn lead to significant differences in moral rules. An analogy to this problem lies in classical geometry, which relies upon certain axioms about how line segments and angles add together, how parallel lines relate to each other, and so on. Given these axioms, all kinds of consequent theorems can be derived that compose the main body of classical geometry. Other axioms lead to other kinds of geometries, however.