As it strives to join the European Union, Turkey is being forced to recognise it is not as fully Turkish as years of political teaching led it to believe.
Concessions on the long-restricted use of minority languages such as Kurdish, part of sweeping human rights reforms aimed at winning Ankara a start date for EU entry talks, are still very limited by many countries' standards.
But they go to the very heart of Turkey's self-image as a purely Turkish nation, which for years referred to its estimated 12 million ethnic Kurds as "mountain Turks".
The Turkish population is 70 million.
"This much change in such a short time is almost revolutionary," said Mr Dogu Ergil, professor of political sociology at Ankara University.
In the past two years the Turkish government has eased tight restrictions on the use of languages such as Kurdish, Arabic, Bosnian and Circassian, including ending a ban on broadcasting and language teaching, aiming for a "yes" when EU leaders decide in December whether to start entry talks.
Kurdish, an Indo-European language unrelated to Turkish, is especially sensitive because of a 20-year separatist conflict in southeast Turkey that has killed more than 30,000 people.
Ankara has kept a tight lid on use of the language for decades, seeing it as a political rallying point.
"That philosophy has allowed the stifling of social culture, traditions, languages, beliefs, and politicised it.
It became a matter of basic rights and freedoms," Mr Ergil said.
During the 1980s it was technically illegal to speak Kurdish at all. Now it is heard openly in the street and some Kurdish magazines and books are available, along with Kurdish music.
"Compared to a few years ago we feel lucky," said Mr Aydin Unesi, who started Turkey's first legal Kurdish language courses in April in the southeastern town of Batman.
"The things being done are not adequate but they are all positive," he added.