A principle formulated in 1894 by Pierre Curie (1859–1906) stating that: (a) If certain causes yield known effects, the symmetry elements of the causes should be contained in the effects generated; (b) If there is an absence of symmetry elements in the known effects, that absence should be contained in the causes which generated those effects; (c) The effects may have higher symmetry than the causes which generated them, therefore the converse of (a) and (b) is not true. See also sander’s symmetry principle.