I believe that while voters don't see the environment as an overt national priority, they do see it as an underlying sine qua non — something that has to be looked after, that has to underpin everything else. (newscientist.com)
All-or-none reward training is the quintessence — the sine qua non — of successful adult dog training. (dogstardaily.com)
However one understands that claim (and the kind of exclusivist Christology dominant in the neo-orthodox period is neither the sole nor the proper way to understand it), one must, qua theologian, find some means of coming to terms with universalism. (religion-online.org)