Historic conservation now needs re-examination of its basic concepts

The period from the Venice Charter of 1964 to Nara Conference on Authenticity of 1994 saw many increases and enlargements of concepts in historic conservation, which corresponded to wider spread of the idea of historic conservation around the world. Yet, the period from Nara Conference till now witnessed rather clashes of ideas concerning historic conservation. Contrary to our expectation, the concept of authenticity secured no firm foundation even after the conference. The debates on intangible heritage, the original theme for the scientific symposium in 2002, also showed a deep conceptual rift among ICOMOS executives. Now at many conferences on historic conservation we frequently see such conceptual clashes. What is the cause of these clashes?