Humans have always needed and wanted food, clothing, shelter, and sex, but often lack a concept of value or goodness by which to understand and think about such things or about the role such things play in our lives, therefore makes the activity of evaluating lies at the center of human affairs. Even if we do not think of the physical universe as containing ends or purposes, human activities can only be understood in terms of purposes. The scientific study of the universe and the life it, is undertaken only because it is valued –whether merely to increase understanding or, as in modern time (for better or worse), to let us harness the world’s resources to human needs. We can, in short, neither live as rational beings nor fully understand our personal and social lives apart from the idea of value.
Making sound and reasonable judgements with respect to moral problems depends on how well the principles and procedures of logic are employed. The level of the logical skill brought to bear on a moral problem or moral puzzle goes, to a large extent, to determine the plausibility of the eventual approach adopted to resolve the problem or puzzle
We attempt to apply the methods, principles and procedures of logic for resolving the conflicts and problems that arise in real-life moral (practical) situations. Again, moral reasoning demonstrate the social relevance and practical utility of logic. When moral conflicts are most likely to accept the decision (or conclusion) arrived at. It is only via such rational means of resolving moral conflicts that we can avoid such social ills like discrimination, hatred, injustice, riot, and war.
Issues such as whether an action is good or bad, whether it is commendable or condemnable, whether it is right or wrong, whether it is what we ought to do or what we ought not to do are essential, and when there is disagreement, we have an evaluative moral disagreement. For instance; if I say: polygamy is good; it makes the wives (women) compete in caring for the husband (man), and teaches the wives (women) tolerance. And you respond by saying: Polygamy? It is bad; it create jealousy and envy amongst the wives (women); thus create separation in the family.
The disagreement here is over the value of family, which you and I identify differently. For me, polygamous family is good while for you, it is bad. Until we reconcile our differences in the goodness or value of family, we will be unable to agree on the moral evaluation of family.