Moral realism is a philosophical point of view which states that there are moral facts that can and should be acted upon. This type of philosophy is dependent on a number of different variables and questions, all of which have to be answered in order for moral realists to accept the moral fact. In the end, the goal of moral realism is to determine objective moral values. This is done by answering the question: If there are moral facts, how can they be discovered?
Moral realism, while having a significant following, has other forms of philosophy that are in direct contrast to its stated claims. Those who question moral realism are referred to as anti-realists. Such people have significant problems with the theories posed by moral realists and wish to subscribe to other types of philosophy. Anti-realists often are further broken down into a number of subcategories.
The first step in moral realism states that some moral sentences are true. This assumes, of course, that such things can be evaluated. For example, saying, "Murder is wrong" is a sentence that moral realists would have to determine if it is true or not. To do so, they would first have to decide whether the truth of the sentence could be evaluated.
If the moral statement can be evaluated, the next step to determine if it is true lies in looking at its real-world relationships. For example, moral realism may perform what amounts to a cost/benefit analysis to determine if murder is wrong. What does it harm the individual? What does it harm society? How are these quantifiable? Are there any advantages or positives to murder? All these questions would need to be answered.
If the answer reveals that there is a real-world relationship, then in the minds of a moral realist, there are other quantifiable statements that have absolute moral authority. Thus, moral realism states that judgments can be made about these issues, based on the validity of the moral statement. However, before judgments can be made, every statement must be thoroughly vetted.
The opposition to moral realism that anti-realists have can best be explained through the feelings of the noncognitivist. These individuals believe that moral statements can only be accepted or rejected based on one's own personal beliefs, convictions and emotions. Therefore, there may truly be no way to objectively answer the question of if there is a real-world relationship that can be linked to a moral statement.