What is morality? Morality is “the differentiation among intentions, decisions, and actions between those that are good (or right) and bad (or wrong)” (Morality, 2010). Thus, moral philosophy is that branch of study concerning whether what a human does, decides, and acts is good (or right) or bad (or wrong).
But how do we define good and bad? How do we decide our action is right or wrong? How do we measure what we do is right or wrong? If we decide to help people, it is considered a good decision leading to right action. If we do not decide to help people when we should, it is considered a bad decision leading to wrong (or no) action. But what actually motivates us to decide to help others? Where does this motivation come from? In other words, what is the driving force behind being good?
It appears that the driving force of motivation for good or bad is our natural instinct of survival. For example, a man kills a person. This is a wrong. He must not kill as killing is forbidden because God says that we must not kill. But because the culprit first tries to kill him this forces him to naturally protect himself by killing this intruder in order to survive. So killing in this case is neither good nor bad as it depends on circumstances. Another example is a life-threatening highly infectious virus found in the body of a group of people. This virus could not be destroyed by medical means and must be quickly terminated else it would spread and destroy the entire human species. Thus, the decision to kill this group of people to terminate the spreading of the virus is not wrong but right, and the effect is not bad but good. So, no decision that leads to action is considered absolutely right or wrong - all decisions are in fact neutral. Moral philosophy is thus the interpretation of an action whether or not it conforms to a standardized set of values and principles, known as moral principles that determine whether our decision leading to action is right or wrong.
There are many moral principles established according to religious belief. For example, in the Buddhist view, one must not kill animals or eat their flesh. This is considered an act of unkindness. So the moral philosophy of Buddhism is that killing animals is wrong. But for most people, animals like pigs, cows, goats, etc., are created by God for humans to consume. There are thus no moral principles, other than the Buddhist or other views, that say killing and eating these animals is wrong - in fact it is right because they provide food and nutrients for body needs. For the Muslims, however, they can eat most kinds of eatable animals except pigs that are considered bad. But for others such as Christians, pig can be eaten and in fact is good because it is cheaper and tastes better than most eatable animals. Thus, different religious beliefs of people establish different moral principles.
Other moral principles are also established by people of different races, customs, and political background. These moral principles, including our natural instinct for survival as depicted above, become the backbones of our moral philosophy and are the powerful motivating force behind all our actions. And no single moral philosophy is considered absolute as it is related to the fundamental perceived beliefs, values, and principles that have been developed and modified from time to time by people of different races, customs, political and religious background since the first pair of humans walked on planet earth.