In 2008, the Italian government passed a law that introduced a new school subject: Citizenship and Constitution. The law requires all students between the ages of 3 and 16 to attend almost 400 hrs. of Citizenship Education during their 13 years of compulsory schooling. The law is part of an increasingly wider international effort that focuses on improving pupils' knowledge of and involvement in society by exposing them to history and civic content. The aim of this article was to present a Citizenship Curriculum and its possible implementation in schools and other areas. Taking into account the Curriculum Transposition model, we propose both an External Transposition, which analyses international and national documents about Citizenship Education, and an Internal Transposition, in order to design a curriculum that will enable children to participate in decision-making processes and improve their complex thinking. The Implemented Citizenship Curriculum ("Poli§ophia" project) was introduced into the Municipal Council of Children, and the Philosophy for Children method was applied in order to help children make moral judgments, a fundamental component of democratic thinking.