"It's against nature".

A couple of years ago, a physician involved in the Ashley case launched a presentation about it at a bioethics conference by dismissing one of the stupider objections, as he saw it, to the interventions Ashley's parents had requested. Ashley is a profoundly cognitively disabled child; her parents sought and obtained interventions, both surgical and pharmacological, that effectively stalled her physical development at a prepubescent stage. The dismissed objection had this form: "These interventions are against nature, and therefore wrong." The presenter did not analyze the objection; he just said he didn't buy it. I don't either. On the other hand, I do find myself swayed by a concern of some sort about what human beings do to nature, including to human nature. I think it's better to leave great old trees standing than pointlessly to chop them down, better to leave a patch of prairie than to pave it over, better to let species carry on than to bring about their extinction. I take a fairly dim view of breast augmentation, nose jobs, Botox, skin bleaching, and drug-enhanced muscle building. What stops me from saying that those things are "against nature, and therefore wrong," is an assortment of complexities that require a much more nuanced and qualified comment. First, a conceptual complexity. To say that an action is "against nature" implies that one has a clear understanding of what "the natural" is and of how and when human action is counter to it, but mostly we lack that. In fact, we use the word "natural" in ways that are sometimes starkly inconsistent with each other. In one use (suggested by examples like felling forests and paving prairies), human action is always counter to nature: it always changes the world. But we might also hold that human action is always natural: it always conforms to the laws of nature. In another use, "natural" refers to how we change the world, and whether a given activity is appropriately called "natural" depends on the context in which the activity is considered. Chopping down trees looks to be at odds with the goals of a "nature preserve," but it might be quite compatible with organic agriculture. This is a looser way of using the word "natural": calling a state of affairs "natural" indicates that human intervention into it is constrained or absent, but allows that the difference between "natural" and "unnatural" is a matter of convention, informed by what we know about the world and human needs, and understood in ways specific to particular contexts--environmental management, agriculture, child-rearing, human reproduction, sex, athletic performance, and so on. Lacking any one clear definition of "natural," we would have to explain the concept by looking at examples, and while some cases might provide touchstones, there might be many cases where the terms are underdetermined. Understanding "nature" and "human nature" along these lines means that these concepts do not have all the baggage of "essentialism"; there is no thought that in grasping the concept we have grasped the ultimate truth about a discrete category of things in the cosmos--that we know what it really means to be human, or what separates human from everything else in the universe. There is nothing eternal, immutable, or rationally necessary about them. Indeed, the line between "natural" and "not natural" will be fundamentally contestable. People will disagree about many in-between cases, with no definitive resolution in sight. Given these limits, calling an intervention "against nature" sounds wrong. For starters, it seems to point to a much more rigid conception of nature. It's also just too cocksure. It does not recognize the contestability of this concept. The conceptual complexity strikes me as a difficulty even in making sense of a moral concern about nature, but it is not the chief problem with formulating that concern by saying bluntly, "That's against nature, and therefore wrong. …