Abstract
The paper addresses a question concerning George Ellis’s theory of top-down causation by considering a challenge to the “level-picture of nature” which he employs as a foundational element in his theory. According to the level-picture, nature is ordered by distinct and finitely many levels, each characterised by its own types of entities, relations, laws and principles of behavior, and causal relations to their respective neighbouring top- and bottom-level. The branching hierarchy that results from this picture enables Ellis to build his model of modular hierarchical structure for complexity, his account of same-level, bottom-up and top-down causation, of emergence, equivalence-classes and multiple realisability. The three main arguments for the level-picture in Ellis’s works are reconstructed and shown to face serious problems. Finally, the paper presents a possible solution to this challenge by introducing a reformulation of certain fundamental points of Ellis’s theory that does without the level-picture of nature. This allows us to preserve all of his central claims about the model of complexity, the three types of causation, emergence, equivalence-classes and multiple realisability. Any problems pertaining to the level-picture can be remedied in the context of Ellis’s theory of top-down causation.