A theoretical system does not merely state facts which have been observed and that logically deducible relations to other facts which have also been observed.
Talcott ParsonsSociology should... be thought of as a science of action-of the ultimate common value element in its relations to the other elements of action.
Talcott ParsonsIt is that of increasing knowledge of empirical fact, intimately combined with changing interpretations of this body of fact - hence changing general statements about it - and, not least, a changing a structure of the theoretical system.
Talcott Parsons