Both the talk, and the lively discussion following, focused on the idea of a Two-speed Europe, which would reflect the preferences of the European people and which is best realised in the constitutional model of concentric circles. A constitution following this concept would be based on civil liberties and the common European market. The European Constitutional Group, of which Prof. Kirchner is a member, developed this as a proposal for a revised European constitutional treaty. It would allow further integration driven by small groups of member states.
Prof. Kirchner's presentation can be found:
Europäischer Verfassungsvertrag - ein gescheitertes Projekt?
The Proposal of the European Constitutional Group:
Proposal for a Revised Constitutional Treaty