Christian ethics is a branch of Christian theology that defines concepts of right (virtuous) and wrong (sinful) behavior from a Christian perspective. Various sources inform Christian ethics, including Judaism and pagan ethics (as well as identifying the limits of the latter), and the life of Jesus. "Comprehensive Christian ethical writings use four distinguishable sources: (1) the Bible and the Christian tradition, (2) philosophical principles and methods, (3) science and other sources of knowledge about the world, and (4) human experience broadly conceived." Although Christian ethics is informed by numerous sources, the Christian Bible, both Old and New Testaments, figures prominently. According to Long, "Christian ethics finds its source in diverse means, but it primarily emerges from the biblical narrative" which includes various accounts in the Old Testament, of which Christians hold different views. According to The Westminster Dictionary of Christian Ethics, "The Bible is the universal and fundamental source of specifically Christian ethics."