— Roger Wolcott Sperry American neuroscientist 1913 - 1994
Context: Science traditionally takes the reductionist approach, saying that the collective properties of molecules, or the fundamental units of whatever system you're talking about, are enough to account for all of the system's activity. But this standard approach leaves out one very important additional factor, and that's the spacing and timing of activity — its pattern or form. The components of any system are linked up in different ways, and these possible relationships, especially at the higher levels, are not completely covered by the physical laws for the elementary interactions between atoms and molecules. At some point, the higher properties of the whole begin to take over and govern the fate of its constituents.
A simple way to illustrate this idea is to imagine a molecule in an airplane flying from L. A. to New York. The molecule may be jostled somewhat or held in position by its neighbors, but these lower-level actions are trivial compared to its movement as the plane flies across the continent. If you plot the movement of the molecule through time and space, those features governed by the higher properties of the plane as a whole make those controlled at the level of the molecule insignificant by comparison. The higher properties control the lower, not by direct intervention, but by supervention.