This work is an examination of teleological attributions i.e. ascriptions of proper functions and natural ends) to the features and behavior of living things with a view to understanding their application to human life.

Nature and Normativity argues that the problem of the place of norms in nature has been essentially misunderstood when it has been articulated in terms of the relation of human language and thought, on the one hand, and the world described by physics on the other. Rather, if we concentrate on the facts that speaking and thinking are activities of organic agents, then the problem of the place of the normative in nature becomes refocused on three related questions. First, is there a sense in which biological processes and the behavior of organisms can be legitimately subject to normative evaluation? Second, is there some sense in which, in addition to having ordinary causal explanations, organic phenomena can also legitimately be seen to happen because they should happen in that way, in some naturalistically comprehensible sense of ‘should’, or that organic phenomena happen in order to achieve some result, because that result should occur? And third, is it possible to naturalistically understand how human thought and language can be legitimately seen as the normatively evaluable behavior of a particular species of organism, behavior that occurs in order to satisfy some class of norms? This book develops, articulates, and defends positive answers to each of these questions.

The components of living systems strike us as functional-as for the sake of certain ends—and as endowed with specific norms of performance. The mammalian eye, for example, has the function of perceiving and processing light, and possession of this property tempts us to claim that token eyes are supposed to perceive and process light. That is, we tend to evaluate the performance of token eyes against the norm described in the attributed functional property. Hence the norms of nature. What, then, are the norms of nature? Whence do they arise? Out of what natural properties or relations are they constituted? In Norms of Nature, Paul Sheldon Davies argues against the prevailing view that natural norms are constituted out of some form of historical success—usually success in natural selection. He defends the view that functions are nothing more than effects that contribute to the exercise of some more general systemic capacity. Natural functions exist insofar as the components of natural systems contribute to the exercise of systemic capacities. This is so irrespective of the system's history. Even if the mammalian eye had never been selected for, it would have the function of perceiving and processing light, because those are the effects that contribute to the exercise of the visual system. The systemic approach to conceptualizing natural norms, claims Davies, is superior to the historical approach in several important ways. Especially significant is that it helps us understand how the attribution of functions within the life sciences coheres with the methods and ontology of the natural sciences generally.

An introduction to natural law theory and a challenge to re-think current biblical scholarship on the topic. Levering establishes the relevance of a biblical worldview to the contemporary pursuit of a moral life and locates his argument in the context of the philosophical development of natural law theory from Cicero to Nietzsche.