Pyschiatrist Randolf Nesse is a gifted writer who I have followed for many years. I first learned of Nesse's work when I read Why We Get Sick: The New Science of Darwinian Medicine. Nesse is one of the many respondents to this year's annual question by Edge.org: "What will change everything?" Nesse's answer: RECOGNIZING THAT THE BODY IS NOT A MACHINE As we improve our knowledge of bodies, they don't fit very well within our venerable metaphor of the body as a "machine." One of his points is that we can describe machines, whereas a satisfying description of bodies seems so elusive. The complexity of the body is, indeed, humbling:

We have yet to acknowledge that some evolved systems may be indescribably complex. Indescribable complexity implies nothing supernatural. Bodies and their origins are purely physical. It also has nothing to do with so-called irreducible complexity, that last bastion of creationists desperate to avoid the reality of unintelligent design. Indescribable complexity does, however, confront us with the inadequacy of models built to suit our human preferences for discrete categories, specific functions, and one directional causal arrows. Worse than merely inadequate, attempts to describe the body as a machine foster inaccurate oversimplifications. Some bodily systems cannot be described in terms simple enough to be satisfying; others may not be described adequately even by the most complex models we can imagine.