We require every man in the Army, for that is the 'sine qua non' of victory.
It is the sine qua non of any hopeful outlook for the future of mankind.
A sine qua non is that the glass be hot enough to melt the shellac.
This is a sine qua non, if the nitrate is to get a fair chance.
Morality had a vogue in those days, was a sine qua non of fashion.
Adaptability is therefore ...