Although a great deal of the best work in bioethics has involved the application of certain ethical principles — such as respect for autonomy, beneficence, and justice — to particular issues of concern, there is no way to apply principles in a vacuum. How we understand such principles, and how we understand the situations we encounter, will depend on background beliefs that we bring to moral reflection — beliefs about the meaning of human life, the significance of suffering and dying, and the ultimate context in which to understand our being and doing. Our views on such matters are shaped by reasoned argument and reflection less often than we like to imagine. Our background beliefs are commonly held at a kind of prearticulate level. We take them in with the air we breathe, drink them in from the surrounding culture. It is, therefore, useful sometimes to call to mind simply and straightforwardly certain basic elements in a Christian vision of the world — to remind ourselves of how contrary to the assumptions of our culture that vision may be. Hence, before we turn in the following chapters to complicated issues in bioethics, we do well to reflect briefly upon some of our background beliefs.