sine qua non

What I did in the meantime — because I knew that I had to be there and eat the food, and know the people, and that was sine qua non.

Impartiality is the sine qua non for any jurist, therefore, the privilege of a lifetime appointment requires strict avoidance of even the slightest appearance of partisanship.

But a first hostage deal “is the sine qua non of the administration’s larger regional deal,” said Martin S. Indyk, a former U.S. ambassador to Israel.

For those actors who consider crying to be the sine qua non of their art, a sorrowful biography offers a distinct advantage in the Method acting sweepstakes.

It’s the sine qua non of public-spirited medical options, and it’s our shame and misfortune that it has been redefined by the Paxtons of this world as a strictly personal choice.