While it appears in some quarters that epigenetics is a new approach in science, it is a phenomenon discussed even by Aristotle. An epigenetic approach holds that all response systems are synthesized during ontogeny and that this synthesis involves the integrative influence of both intraorganic processes and extrinsic stimulative conditions. It considers gene effects to be contingent on environmental conditions and regards the genotype as capable of entering into different classes of relationships depending on the prevailing environmental context. In the epigeneticist's view, the environment is not benignly supportive, but actively implicated in determining the very structure and organization of each response system. This article asks the question: How can it be that clear evidence exists for both function-driving-structure as well for structure driving-function? The likely answer presented here is that both effects are at play and are part of an overarching principle in which the mutual interplay of structure and function at multiple levels influences gene expression.