For me, politeness is a sine qua non of civilization. Robert A. Heinlein
Taking charge of your own learning is a part of taking charge of your life, which is the sine qua non in becoming an integrated person. Warren G. Bennis
Fidelity to the subject's thought and to his characteristic way of expressing himself is the sine qua non of journalistic quotation. Janet Malcolm
Winning the Revolutionary War, or the Civil War, or World War II were the turning points in our history, the sine qua non of our forward progress. Stephen Ambrose
Sound money is the sine qua non of a prosperous society. Arthur Laffer
