Tacit Creationism Encourages Oversimplified Views of Functions and Dysfunctions.

Notions of function and dysfunction are fundamental for neuroscience, psychology and psychiatry but remain contentious. We propose that some of these controversies arise from 'tacit creationism', which disavows a designer but nonetheless views bodies and brain-minds as if they are products of conscious planning with discrete parts that serve specific functions. Many philosophers agree that 'failure to perform a normal function' is fundamental to the concepts of physical disease and mental disorder. However, unlike machines and computers, no blueprint defines a single normal phenotype for bodies and brain-minds. Instead, varying genes interact with one another and environments to create individuals who vary in ways that give advantages and disadvantages that depend on the environment. Many clinically relevant variations influence the gain in control systems for adaptive responses such as anxiety and low mood, making it difficult to draw a bright line between normal and excessive activation of distressing emotions in a particular context. Literal interpretations of the metaphor of body as machine or brain-mind as computer encourage essentializing normality and pathology-expecting functions to be as specific as those for parts of machine and dysfunctions to involve discrete anatomo-physiological or molecular defects corresponding to broken parts. Rejecting tacit creationism, and accepting the messy reality of organic complexity, the fuzzy boundaries of disorders and the multiple difference-makers that contribute to pathogenesis offers a better way forward for neuroscience, psychology and psychiatry.