Can a whole change its components top-down? With a whole constituted of components (or parts), top-down chan-ges should originate at the whole (assigned to system level n) and affect the components at the level below (level n-1, "the bottom"). Top-down experiments search for such chan-ges in natural mechanisms. They require (a) primary interaction of a peer object with the mechanism as a whole, which is (b) followed or accompanied by a change among its compo-nents. It is often claimed that such experiments or observations (of swarm behaviour, for instance) have shown that a whole can indeed change the properties of its parts. However, all the top-down experiments and observations considered here turn out to have alternative explanations of the bottom-bottom plus bottom-up type. To account for this disconcerting result, I argue that a constituted whole necessarily depends in existence and all properties on its components and their relations and only on them. This restriction implies that, contrary to expectation, a constituted whole (a) cannot be subjected to a not-constitutive top-top change. Nor can it then (b) effect a top-down inverse-constitutive change, as the constitu-tive relation of mechanisms is shown to be asymmetric (bottom-up only). (Proof included.) Nor can the whole (c) effect a top-down causal change, as a whole cannot encounter the components, which it inseparably contains, for interlevel interaction. For these reasons mutual manipulability of whole and components of mechanisms, which the literature claimed repeatedly, is not possible, top-down changes directed from whole to components remain elusive in theory and practice. Related issues, foremost the nature of constituted wholes and the nature of system levels, are discussed.
About the Author: Bernd Lindemann studied Medicine in Tubingen and Munich, Germany, and gained his MD at the University of Hamburg with a paper on ion transport (1959). He held a research position at the Department of Biophysics, Harvard Medical School and at the Department of Biochemistry, Frankfurt, before becoming a Professor of Physiology at the Medical Faculty, Universitat des Saarlandes (1970). His research topic was the biophysics of ion movement across cell membranes, later the signal transduction in the sensory cells of olfaction and taste. He published about120 peer-reviewed research papers and reviews. Following his retirement in 1998 and a term as research professor in Fukuoka, Japan, Bernd Lindemann took an interest in the Philosophy of Neuroscience, centred on the relationship of brain-biophysical and mental phenomena."