Worldview and Ethical Reasoning
Cogent and persuasive ethical reasoning presupposes a worldview and standards of judgment. It is not easy to argue these from nature alone. For Christians, these standards come from Scripture. So apart from Scripture, ethical argument loses its cogency and often it’s persuasiveness. Nonbelievers, of course, won’t usually accept Scripture as authoritative. But they may at least respect an argument that is self-conscious about its epistemological and metaphysical presuppositions.
In public discussion, it may sometimes be desirable to argue a position without directly referring to Scripture. We may, for example, point to the cultural consequences of China’s one-child policy, or to the general indifference to human life encouraged by legalized abortion, or to the societal consequences of secularized education. Arguments like these will be persuasive to some non-Christians. They appeal to that knowledge of natural revelation that they are unable fully to suppress. But when someone presses us to ask, for example, why we think that indifference to human life is a bad thing, we must in the end refer to Scripture, for that is the ultimate source of our values.