There are two sorts of truth: trivialities, where opposites are clearly absurd, and profound truths, recognised by the fact that the opposite is also a profound truth
Niels BohrThe measurement we get when we measure something is not a property of the thing measured.
Niels BohrOur task is not to penetrate the essence of things, the meaning of which we do not know anyway, but rather to develop concepts which allow us to talk in a productive way about phenomena in nature
Niels Bohr