The hypothesis may be put forward, to be tested by the s subsequent investigation, that this development has been in large part a matter of the reciprocal interaction of new factual insights and knowledge on the one hand with changes in the theoretical system on the other.

Spencers god was Evolution, sometimes also called Progress.

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.

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 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.

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

Theory not only formulates what we know but also tells us what we want to know, that is, the questions to which an answer is needed.