Science is intimately integrated with the whole social structure and cultural tradition. They mutually support one other-only in certain types of society can science flourish, and conversely without a continuous and healthy development and application of science such a society cannot function properly.

It 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.

But the fact a person denies that he is theorising is no reason for taking him at his word and failing to investigate what implicit theory is involved in his statements.

It 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.

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.

The implications of these considerations justify the statement that all empirically verifiable knowledge even the commonsense knowledge of everyday life - involves implicitly, if not explicitly, systematic theory in this sense.

The part an actor played on stage was once written on a separate roll of paper.