Refers to the study and practice of what it is to live a valuable human life and the subsequent codes or systems of values. The term ‘ethics’ is closely related to the term ‘morals’, and the two can be used interchangeably for all but the most academic purposes. Indeed, theologically based ethics is often referred to as moral theology, and philosophically based ethics is often referred to as moral philosophy. The etymological roots of the terms ‘ethics’ and ‘morals’ do, however, reflect a shift in the meaning and treatment of the subject that is worth noting. ‘Ethics’ comes from the Greek word ethos meaning character, whereas ‘morals’ comes from the Latin morales meaning custom or behavior. The emphasis in the first instance is on one’s character and how it is best to be as a person, including the actions which one ought or ought not perform since these actions shape one’s character. The emphasis in the latter instance, i.e., in the context of ‘morals’, is more specifically on what it is best to do. Too narrow a focus on this latter meaning is one reason why ethics has come to be inappropriately characterized as the study of moral dilemmas. While the resolution of dilemmas or "hard cases" is one piece of the total purview of ethics, ethics can be best defined as, "the science and art of making beneficial human decisions; decisions that help individuals fulfill their innate and cultural needs" [Kevin O’Rourke, "Institutional Ownership as an Ethical Issue," in Healthcare Ethics: A Guide for Decision Makers (Aspen Publishers, 1987)].
Ethics is generally the business of justifying one decision to act over another. There are three basic ways of justifying what one believes to be beneficial human decisions: top-down, bottom-up, or coherence methods of justification. Coherence methods of justification begin from considered moral judgments, intuitions, or mid-level principles (principles that are neither foundational nor specific action guides, e.g., beneficence) that are held in common. A decision to act is then brought into an ordered state of coherence with these initial judgments, intuitions or principles. This coherence is developed through a process known as "reflective equilibrium." For example, the "four principles approach" to health care ethics utilizes this kind of justification.
Bottom-up methods of justification begin with the specific circumstances and contextual nuances of concrete cases and then look to the resolution of similar cases for guidance on how to resolve the present case. From these previous resolutions of similar cases, patterns emerge and mid-level principles and sometimes comprehensive theories of moral value emerge. High Casuistry is an example of an ethical theory that employs the bottom-up method of justification.
Top-down methods of justification, or deductivist methods, begin with a foundational theory of moral value, from which mid-level principles are deduced. From these mid-level principles, ethical rules of conduct are derived. These rules of conduct are then used to determine particular judgments of what actions should or should not be performed. Ethical theories that utilize the top-down method of justification can be broken down into three broad categories: Consequentialism, Deontology, and Teleology.
While these considerations are indeed very philosophical, Catholic moral theology has always relied heavily on philosophical tools. During the late Patristic and early Medieval periods (4th century to 12th century), Plato’s philosophy was the dominant philosophical influence on Catholic moral theology, in particular, through the writings of St. Augustine. During the high middle ages, Aristotle became the dominant philosophical influence through the work of St. Thomas Aquinas. It is in the Thomistic synthesis of Aristotelian thought and Christian theology that the Natural Law theory that has been central in Catholic moral theology has its foundations. From the 16th to the mid 20th century, Catholic moralists moved away from Thomism and tended to focus on the application of principles to cases, a method known as casuistry. Largely because it was considered too legalistic and formalistic, casuistry fell into disfavor in the second half of the 20th century. Contemporary Catholic moral theology has since returned to an emphasis on the insights of Aristotle and St. Thomas. Most recently, phenomenology with its emphasis on human dignity has been a major influence through the Papacy of John Paul II.
Outside of Catholic moral theology, there are many significant sources of influence on contemporary ethical thinking in the United States, both theological and philosophical. Jewish moral teaching, for example, is based on Torah (the law of Hebrew Scriptures) and Rabbinical commentary and case studies in the Talmud. Classical Protestant moral theology, particularly in its Calvinist form, puts little or no trust in Natural Law reasoning because of its emphasis on total depravity wrought by Original Sin. Most forms of Protestantism, then, rely exclusively on the moral laws and exhortations of Scripture as the source of moral guidance. More recent years have witnessed a "rapprochement" between Catholic and protestant methods, as well as between Christian and Jewish thought. Islam relies on the Quran for its principle source of teaching but, like Judaism and Christianity, has many different interpretations.
The philosophical movement in the 18th century known as the "Enlightenment," which ushered the period of Modernity, brought with it the Copernican Turn, a new scientific perspective (namely, that nature is governed by absolute laws), the dominance of Cartesian Dualism and the "Naturalistic Fallacy." With these changes in the prevailing worldview, the Enlightenment brought about the rejection of the metaphysical views on which teleological moral methods such as Natural law traditionally depended. Since this time, modern western philosophical ethics has been dominated by a duty-based or deontological approach. Such an approach lends itself to an impartial "ethic of justice." Recently, however, feminist critical thought and a resurgence of interest in Virtue Ethics has brought into question the tenets of the dominating deontological methods. Consequentialism has also had a profound influence on contemporary American thought, including Catholic Scholarship. Consequentialism and Deontology, however, both claim to specify a fundamental source of moral value and often lead to irresolvable conflicts. Much work in contemporary moral philosophy is dedicated to developing a systematic method of adjudicating between these competing claims. Because how one weighs these competing claims depends largely on one’s own philosophical, theological, and cultural perspectives, some thinkers believe that either there are no objective moral values whatsoever or that we cannot know what the source of moral value is. Thus, according to these thinkers, the only source of moral value available in the public sphere of ethics is agreement or consensus. This movement is what is known as Post-modernism and is dominated by ethical relativism and nihilism.