If there are four equations and only three variables, and no one of the equations is derivable from the others by algebraic manipulation then there is another variable missing.
Talcott ParsonsIt is probably safe to say that all the changes of factual knowledge which have led to the relativity theory, resulting in a very great theoretical development, are completely trivial from any point of view except their relevance to the structure of a theoretical system.
Talcott ParsonsThe importance of certain problems concerning the facts will be inherent in the structure of the system.
Talcott Parsons