idée mère

plural idées mères

1. A fundamental idea or guiding principle, seen as giving rise to something.First known use 19th c.

   The idée mère, the primitive element, in the formation of the notion of justice, was conformity to law.

   1863, John Stewart Mill, Utilitarianism, section V

   1 more example

   M. Malot pursues this physiological development of his idée-mere with a good deal of skill, and it is, we think, the most interesting feature of his book.

   1868 September 26, The Saturday Review

   Synonyms: mother idea