M.E Opler has put forward the concept of themes to explain integration. Themes are defined as general motivations which are responsible for various sets of behaviour types in a society. His themes are not tied down to any types ; he leaves that to every field investigator to find out for himself .
Themes are the specific expressions of cultural integration in each individual case.Opler illustrated how this concept may be used in his account of the Apache life way. The concepts of patterns and themes are both keys to the specific structure and character of a way of living.