This essay pushes the discussion of biology and altruism in radical directions by highlighting the moral ambiguity of biology itself. The extent to which we draw positive moral implications from animal behavior, and even the extent to which we see positive traits in animals, is shaped by the preconceptions and the purposes one brings to the study. These preconceptions, when examined, involve worldview issues that are all related in one way or another to either a theological position or some nontheistic substitute for an account of ultimate reality. It is arguable that Darwin's own perceptions of nature were colored by the theological and social-ethical context in which he worked. William Paley's natural theology, together with Thomas Malthus's Essay on the Principle of Population, led many theologians of Darwin's day to conclude that struggle, inequality, suffering, and death are basic features of the natural world and are the result of divine providence. No wonder, then, that Darwin was able to see competition as the major key to natural selection. The moral ambiguity of biology can be pressed further by contrasting contemporary attempts to find altruism in animal behavior with the conclusions reached by Friedrich Nietzsche, partly in response to his reading of Darwin. Nietzsche concluded that the standard, more or less Christian, morality of his day is best labeled “slave morality.” It is created by the weak in order to coerce the strong to provide for them. In this essay I contend that competing views of morality can be adjudicated only by turning to an account of ultimate reality. Whether Nietzsche is right in arguing against the morality of altruism depends on whether God is indeed dead.