Moral Philosophy is the discipline concerned with what are ethically good and bad, or right and wrong. The term is also applied to any system or theory of moral values or principles.As this is a subject for thinking, questions are asked and answers are sought: -How should we live? -Shall we aim at happiness or at knowledge, virtue, or the creation of beautiful objects? -If happiness is chosen, will it be our own or for all? What of the more particular questions that face us: -Is it right to be dishonest in a good cause? -Can we justify living in opulence while elsewhere in the world people are starving? -If conscripted to fight in a war we do not support, should we disobey the law? -What are our obligations to the other creatures with whom we share this planet and to the generations of humans who will come after us? Ethics deals with such questions at all levels. Its subject consists of the fundamental issues of practical decision-making, and its major concerns include the nature of ultimate value and the standards by which human actions can be judged right or wrong. The terms ethics and morality are closely related. We now often refer to ethical judgments or ethical principles where it once would have been more common to speak of moral judgments or moral principles. These applications are an extension of the meaning of ethics. Strictly speaking, however, the term refers not to morality itself but to the field of study, or branch of inquiry, that has morality as its subject matter. In this sense, ethics is equivalent to moral philosophy. Although ethics has always been viewed as a branch of philosophy, its all-embracing practical nature links it with many other areas of study, including anthropology, biology, medicine, economics, history, politics, psychology, sociology, and theology. Yet, ethics remains distinct from such disciplines because it is not a matter of factual knowledge in the way that the sciences and other branches of inquiry are. Rather, it has to do with determining the nature of normative theories and applying these sets of principles to practical moral problems.The brief historical survey of Western ethics from Socrates to the 20th century has shown three constant themes. Since the Sophists, there have been: -Disagreements over whether ethical judgments are truths about the world or only reflections of the wishes of those who make them; -Frequent attempts to show, in the face of considerable scepticism, either that it is in one's own interests to do what is good or that, even though this is not necessarily in one's own interests, it is the rational thing to do; -Repeated debates over just what goodness and the standard of right and wrong might be. The 20th century has seen new twists to these old themes and an increased attention to the application of ethics to practical problems. Each of these major questions is considered below in terms of meta-ethics, normative ethics, and applied ethics. Perhaps the greatest legacy of ethics, as an application to a profession, is what Hippocrates has structured as a code of ethics, some two and a half thousand years ago, during the golden age of Hellenism.