Again and again Primo Levi's work is described as indispensable, essential, necessary.
Essential medicines, first proposed by the World Health Organization (WHO) in 1977, were defined as "of utmost importance, basic, indispensable and necessary for the health and needs of the population" and criteria relating to safety, quality, efficacy and affordable [ 1].
"Essential" usually means vital, necessary, indispensable.
"It is an indispensable relationship" for Europe, "necessary but not sufficient" to run Europe's affairs.
the civil action shall not be dismissed, and no relief requested shall be denied, on the ground that the civil action is against the United States or that the United States is a necessary and indispensable party.
In remaking the laws of shipping, insurance and commerce, a thorough familiarity with the customs and practices existing in the world of trade and commerce was, he felt, indispensable, To bring the necessary information to his court, he dared to change the role of the jury drastically.
St. 70, it was held that, as the railroad was exempt from taxation, water stations and depots, including the offices and places to hold cars, etc., being necessary and indispensable to the construction and use of the road, were within the exemption, while warehouses and coal lots, intended for the mere convenience of the road, were not so exempt.
"The balance struck by the [DOJ memo] has been indispensable ― providing the necessary framework for state regulatory programs centered on public safety and health protections".
