The first meeting on the topic of Christian ethics, after the Sermon on the Mount and Great Commission (circa 30), was the Council of Jerusalem (circa 50), which decreed the Apostolic Decree forbiding idolatry, fornication, and blood and things strangled as the minimum requirements for new converts — which is seen by many, begining with Augustine as derived from Noahide Law while some modern scholars reject the connection to Noahide Law and instead see as the basis. See also Old Testament Law directed at non-Jews and Leviticus 18.
Christian ethics developed further while Early Christians were subjects of the Roman Empire. From the time Nero blamed Christians for setting Rome ablaze (64 AD) until Galarius (311 AD), persecutions against Christians erupted periodically. Consequently, Early Christian ethics included discussions of how believers should relate to Roman authority and to the empire, see also Render unto Caesar....
Under the Emperor Constantine I (312-337), Christianity became a legal religion. While some scholars debate whether Constantine's conversion to Christianity was authentic or simply matter of political expediency, Constantine's decree made the empire safe for Christian practice and belief. Consequently, issues of Christian doctrine, ethics and church practice were debated openly, see for example the First Council of Nicaea and the First seven Ecumenical Councils. By the time of Theodosius I (379-395), Christianity had become the state religion of the empire. With Christianity now in power, ethical concerns broaden and included discussions of the proper role of the state, see also Christendom.
Broadly speaking, Saint Augustine adapted the philosophy of Plato to Christian principles. His synthesis is called Augustinianism. In the 13th century, after the recovery of the works of Aristotle, Saint Aquinas reworked the philosophy of Aristotle into a Christian framework known as Thomism.
Christian ethics in general has tended to stress the need for grace, mercy, and forgiveness because of human weakness. With divine assistance, the Christian is called to become increasingly virtuous in both thought and deed, see also the Evangelical counsels. Conversely, the Christian is also called to abstain from vice. There are several different schema of vice and virtue. Aquinas adopted the four cardinal virtues of Plato, (justice, courage, temperance, prudence) and added to them the Christian virtues of faith, hope and charity (from St.Paul, ). Other schema include the Seven Deadly Sins and the Seven virtues. For more see Christian philosophy and Biblical law in Christianity.
The New Testament generally asserts that all morality flows from the Great Commandment, to love God with all one's heart, mind, strength, and soul, and to love one's neighbor as oneself. In proposing this Great Commandment, Jesus Christ was reaffirming the teaching of the Torah. These are well known Old Testament (Jewish) teachings, known respectively as the Shema and the Great Commandment see also Ministry of Jesus#General Ethics and The Law of Christ. Christ brought forth something to the commands by uniting them together and by proposing himself as a model of the love required.
Ecclesiastical writers, as Justin Martyr, Irenaeus, Tertullian, Clement of Alexandria, Origen, Ambrose, Jerome, and Augustine of Hippo all wrote on ethics from a distinctly Christian point of view. Interestingly, they made use of philosophical and ethical principles laid down by their Greek (Pagan) philosopher forbears.
The Church fathers had little occasion to treat moral questions from a purely philosophical standpoint and independently of Christian Revelation; but in the explanation of Catholic doctrine their discussions naturally led to philosophical investigations.
This is particularly true of Augustine, who proceeded to develop thoroughly along philosophical lines and to establish firmly most of the truths of Christian morality. The eternal law (lex aeterna), the original type and source of all temporal laws, the natural law, conscience, the ultimate end of man, the cardinal virtues, sin, marriage, etc. were treated by him in the clearest and most penetrating manner. Hardly a single portion of ethics does he present to us but is enriched with his keen philosophical commentaries. Late ecclesiastical writers followed in his footsteps.
The same is particularly true as regards ethics. Thomas, in his commentaries on the political and ethical writings of Aristotle, in his Summa contra Gentiles and his Quaestiones disputatae, treated with his wonted clearness and penetration nearly the whole range of ethics in a purely philosophical manner, so that even to the present day his words are an inexhaustible source from which ethics draws its supply. On the foundations laid by him the Catholic philosophers and theologians of succeeding ages have continued to build. In his Summa Theologiae, Thomas locates ethics within the context of theology. The question of beatiudo, perfect happiness in the possession of God, is posited as the goal of human life. Thomas also argues that the human being by reflection on human nature's inclinations discovers a law, that is the natural law, which is "man's participation in the divine law."
In the fourteenth and fifteenth centuries, thanks especially to the influence of the so-called Nominalists, a period of stagnation and decline set in, but the sixteenth century is marked by a revival. Ethical questions, also, though largely treated in connection with theology, are again made the subject of careful investigation. Examples include the theologians Francisco de Vitoria, Dominicus Soto, Luis de Molina, Francisco Suarez, Leonardus Lessius, and Juan de Lugo. Among topics they discussed was the ethics of action in case of doubt, leading to the doctrine of probabilism. Since the sixteenth century special chairs of ethics (moral philosophy) have been erected in many Catholic universities. The larger, purely philosophical works on ethics, however do not appear until the seventeenth and eighteenth centuries, as an example of which we may instance the production of Ign. Schwarz, "Instituitiones juris universalis naturae et gentium" (1743).
Lutheran Philipp Melanchthon, in his "Elementa philosophiae moralis", still clung to the Aristotelean philosophy strongly rejected by Luther; so, too, did Arminian Hugo Grotius, in his work, "De jure belli et pacis". But Cumberland and his follower, Samuel Pufendorf, moreover, assumed, with Descartes, that the ultimate ground for every distinction between good and evil lay in the free determination of God's will, a view which renders the philosophical treatment of ethics fundamentally impossible.
In the 20th century, some Christian philosophers, notably Dietrich Bonhoeffer questioned the value of ethical reasoning in moral philosophy. In this school of thought, ethics, with its focus on distinguishing right from wrong, tends to produce behavior that is simply not wrong, whereas the Christian life should instead be marked by the highest form of right. Rather than ethical reasoning, they stress the importance of meditation on and relationship with God.Ethics in the Bible
Western philosophical works on ethics were written in a culture whose literary and religious ideas were based in the Hebrew Bible (Old Testament) and the New Testament. As such, there is a connection between the ethics of the Bible and the ethics of the great western philosophers. However, this is not a direct connection; significant differences of opinion in how to interpret and apply passages in the books of the Bible lead to different understandings of ethics. Some have suggested that modern understandings of the Bible are fundamentally mistaken.
Jewish ethics may be said to originate with the Hebrew Bible, its broad legal injunctions, wisdom narratives and prophetic teachings. Most subsequent Jewish ethical claims may be traced back to the texts, themes and teachings of the written Torah.
Much progress in theoretical ethics came as Jews came into closer contact with the Hellenic world. Before that period the Wisdom literature shows a tendency to dwell solely on the moral obligations and problems of life as appealing to man as an individual, leaving out of consideration the ceremonial and other laws which concern only the Jewish nation. From this point of view Ben Sira's collection of sayings and monitions was written, translated into Greek, and circulated as a practical guide. The book contains popular ethics in proverbial form as the result of everyday life experience, without higher philosophical or religious principles and ideals. More developed ethical works emanated from Hasidean circles in the Maccabean time, such as are contained in Tobit, especially in ch. iv.; here the first ethical will or testament is found, giving a summary of moral teachings, with the Golden Rule, "Do that to no man which thou hatest!" as the leading maxim. There are even more elaborate ethical teachings in the Testaments of the Twelve Patriarchs, in which each of the twelve sons of Jacob, in his last words to his children and children's children, reviews his life and gives them moral lessons, either warning them against a certain vice he had been guilty of, so that they may avoid divine punishment, or recommending them to cultivate a certain virtue he had practised during life, so that they may win God's favor. The chief virtues recommended are: love for one's fellow man; industry, especially in agricultural pursuits; simplicity; sobriety; benevolence toward the poor; compassion even for the brute (Issachar, 5; Reuben, 1; Zebulun, 5-8; Dan, 5; Gad, 6; Benjamin, 3), and avoidance of all passion, pride, and hatred. Similar ethical farewell monitions are attributed to Enoch in the Ethiopic Enoch (xciv. et seq.) and the Slavonic Enoch (lviii. et seq.), and to the three patriarchs.
The Hellenistic propaganda literature made the propagation of Jewish ethics taken from the Bible its main object for the sake of winning the pagan world to pure monotheism. It was owing to this endeavor that certain ethical principles were laid down as guiding maxims for the Gentiles; first of all the three capital sins, idolatry, murder, and incest, were prohibited (see Sibyllines, iii. 38, 761; iv. 30 et seq.). In later Jewish rabbinic literature these "Noachide Laws" were gradually developed into six, seven, and ten, or thirty laws of ethics binding upon every human being.
In the Theravada tradition, on the Buddhist sabbath (uposatha) and festival days, monks administer to laity eight precepts which essentially include the above five precepts (except where, in the third precept, "sexual misconduct" is changed to "sexual activity" for the day) plus the following three:
Theravada monk Bhikkhu Bodhi has observed:
More emphasis is placed on empathy than in other traditions, and women are sometimes upheld not only as great moral examples but also as great gurus. Beyond that, the Mother is a Divine Figure, the Devi, and the aspect of the creative female energy plays a major role in the Hindu ethos. Vande Mataram, the Indian national song (not anthem) is based on the Divine mother as embodied by 'Mother India' paralleled to 'Ma Durga'. An emphasis on domestic life and the joys of the household and village may make Hindu ethics a bit more conservative than others on matters of sex and family.
Of all religions, Hinduism is among the most compatible with the view of approaching truth through various forms of art: its temples are often garishly decorated, and the idea of a guru who is both entrancing entertainer and spiritual guide, or who simply practices some unique devotion (such as holding up his arm right for his whole life, or rolling on the ground for years on a pilgrimage), is simply accepted as a legitimate choice in life.
Ethical traditions in Hinduism have been influenced by caste norms. In the mid-20th century Mohandas Gandhi, a Vaishnava, undertook to reform these and emphasize traditions shared in all the Indian faiths:
After his profound achievement of forcing the British Empire from India, these views spread widely and influence much modern thinking on ethics today, especially in the peace movement, ecology movement, and those devoted to social activism.
Many New Age traditions also derive from his thought and other Hindu traditions such as acceptance of reincarnation, which is a way of expressing the need for reciprocity, as one may end up in someone else's shoes "in a future life". A cardinal virtue in Hinduism is kindness.
This is not to say that there has never been any consideration given to universalist ethics. In fact, in Zhou dynasty China, the Confucians' main opponents, the followers of Mozi argued for universal love, jian'ai. The Confucian view eventually held sway, however, and continues to dominate many aspects of Chinese thought. Many have argued, for example, that Mao Zedong was more Confucian than Communist. Confucianism, especially of the type argued for by Mencius (Mengzi), argued that the ideal ruler is the one who (as Confucius put it) "acts like the North Star, staying in place while the other stars orbit around it". In other words, the ideal ruler does not go out and force the people to become good, but instead leads by example. The ideal ruler fosters harmony rather than laws.
Confucius stresses honesty above all. His concepts of li 理, yi 義, and ren 仁 can be seen as deeper expressions of honesty (cheng 誠, commonly translated as "sincerity") and fidelity (xiao 孝) to the ones to whom one owes one's existence (parents) and survival (one's neighbours, colleagues, inferiors in rank). He codifed traditional practice and actually changed the meaning of the prior concepts that those words had meant. His model of the Confucian family and Confucian ruler dominated Chinese life into the early 20th century. This had ossified by then into an Imperial hierarchy of rigid property rights, hard to distinguish from any other dictatorship. Traditional ethics had been perverted by legalism.
In the Neopagan religion of Wicca, the main ethical basis comes from the Wiccan Rede - do as ye will as long as ye harm none. Wiccan ethics are therefore both liberal and libertarian. Other teachings that influence Wiccan ethics include the Charge of the Goddess and the Wiccan laws (which are usually specific to Gardnerian Wicca).