 That said, Salmon retained the idea of a complete causal structure including all the processes and interactions operating in a certain space-time region. Such a concept bears some resemblance to Peter Railton’s “ideal explanatory text” (Railton 1981), the difference being that Railton has a text in mind, while Salmon’s complete causal structure is a physical entity. The most important feature characterizing the complete causal structure is its objectivity: “the complete causal structure is a fact of nature that exists quite independently of our knowledge or interests” (Salmon 2002: 126).