prime directive

Noun

 * 1) An order or mission which presents the overriding control over a course of action.
 * 2) * 1946: University of Iowa/University of Chicago, The Journal of General Education, p. 160:
 * Such probes would not invalidate the prime directive that a work of art must stand upon its intrinisic artistic merits
 * Such probes would not invalidate the prime directive that a work of art must stand upon its intrinisic artistic merits