If you talk about the ~ of something, you talk about the fact that it does not change or weaken. (WRITTEN)
She believed in the ~ of the class system.
N-UNCOUNT: oft N of n
If you talk about the ~ of something, you talk about the fact that it does not change or weaken. (WRITTEN)
She believed in the ~ of the class system.
N-UNCOUNT: oft N of n
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012