No degrowth without demogaphic degrowth. In ancient civilizations, when epidemics and wars did not suffice, tolerance for celibacy, secular or religious, as well as for homosexuality were mostly resorted to in order to maintain demographic balance. These strategies were frequent in Eastern Asia and are still available to many societies. In the present situation, it seem that China and Vietnam were the only countries which dared to resort to measures – limiting the number of chidren/couple – that seem extreme to our societies structured along religious and caste natalist lines. But they may be the only humane means to achieve a sustainable world demographic growth, short of the unthinkable….