The following article presents preliminary reflections on a processual theory of health and disease. It does this by steering the discussion more toward an ontology of organisms rather than conceptual analysis of the semantic content of the terms "health" and "disease." In the first section, four meta-theoretical assumptions of the traditional debate are identified and alternative approaches to the problems are presented. Afterwards, the view that health and disease are constituted by a dynamic relation between demands imposed on an organism and individual presuppositions for adequate response is developed. In the last section, the paper takes stock of three possible objections to and clarifies some implications of this approach to the notions of health and disease.