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 but "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." Jewish ethics and the life of Jesus also figure prominently. According to D. Stephen Long, "The Bible is the universal and fundamental source of specifically Christian ethics", as "Christian ethics finds its source in diverse means, but it primarily emerges from the biblical narrative.". Christians do not all follow one type of ethics. It depends on their view of Scripture and Tradition.