Mind: A Brief Introduction (John R. Searle) / quote 5 of 138
Observer-independent and observer-relative features
There are two distinctions that I want you to be clear about at the very beginning, because they are essential for the argument and because the failure to understand them has led to massive philosophical confusion. The first is the distinction between those features of a world that are observer independent and those that are observer dependent or observer relative. Think of the things that would exist regardless of what human beings thought or did. Some such things are force, mass, gravitational attraction, the planetary system, photosynthesis, and hydrogen atoms. All of these are observer independent in the sense that their existence does not depend on human attitudes. But there are lots of things that depend for their existence on us and our attitudes. Money, property, government, football games, and cocktail parties are what they are, in large part, because that’s what we think they are. All of these are observer relative or observer dependent. In general, the natural sciences deal with observer-independent phenomena, the social sciences with the observer dependent.