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 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.

The functions of the family in a highly differentiated society are not to be interpreted as functions directly on behalf of the society, but on behalf of personality.

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.

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

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.

Special emphasis should be laid on this intimate interrelation of general statements about empirical fact with the logical elements and structure of theoretical systems.