Two core curriculum concept, which reached its peak popularity in the period between the two World Wars, reflects the child-in-society perspective fairly well. The separate disciplines (as represented by school subjects) are unified in the curriculum through the study of persistent social problems. The disciplines are to serve as sources of expert knowledge and skills. The social problems, to be selected by teachers and students in collaboration with each other, need to be sufficiently important to be concern to all members of society, and of personal relevance to each student as well. Whatever the social problems selected may be, all students, regardless of their ability or background, are expected to study them. This active involvement of students in the investigations and analyses of persistent social problems premises that young people will ultimately and democratically be involved in their resolution.