"Dos aparentemente incompatibles concepciones de la realidad pueden representar un aspecto de la verdad ... Éstas pueden servir de hecho para representar los hechos sin entrar en ningún caso en conflicto entre ellas".
De Broglie (Dialectica) (see also General semantics).

"Two sorts of truth: trivialities, where opposites are obviously absurd, and profound truths, recognised by the fact that the opposite is also a profound truth"
As quoted by his son Hans Bohr in "My Father", published in Niels Bohr : His Life and Work (1967), p.