 Many of the leading issues and positions of contemporary philosophical ethics take shape within the Enlightenment. Prior to the Enlightenment in the West, ethical reflection begins from and orients itself around religious doctrines concerning God and the afterlife. The highest good of humanity, and, accordingly, the content and grounding of moral duties, are conceived in immediately religious terms. During the Enlightenment, this changes, certainly within philosophy, but to some significant degree, within the population of western society at large. As the processes of industrialization, urbanization, and dissemination of education advance in this period, happiness in this life, rather than union with God in the next, becomes the highest end for more and more people. Also, the violent religious wars that bloody Europe in the early modern period motivate the development of secular, this-worldly ethics, insofar as they indicate the failure of religious doctrines concerning God and the afterlife to establish a stable foundation for ethics. In the Enlightenment, philosophical thinkers confront the problem of developing ethical systems on a secular, broadly naturalistic basis for the first time since the rise of Christianity eclipsed the great classical ethical systems. However, the changes in our understanding of nature and cosmology, effected by modern natural science, make recourse to the systems of Plato and Aristotle problematic. The Platonic identification of the good with the real and the Aristotelian teleological understanding of natural things are both difficult to square with the Enlightenment conception of nature. The general philosophical problem emerges in the Enlightenment of how to understand the source and grounding of ethical duties, and how to conceive the highest good for human beings, within a secular, broadly naturalistic context, and within the context of a transformed understanding of the natural world.