“Nevertheless, there remains still in the new kind of theory an objective reality, inasmuch as these theories deny any possibility for the observer to influence the result of a measurement, once the experimental arrangement is chosen.”

in his memoirs, as quoted by [Jean Matricon, G. Waysand, Charles Glashausser, The cold wars: a history of superconductivity, Rutgers University Press, 2003, 0813532957, 18]

Source: Science and Statistics (1976), p. 792

New Pathways in Science: Messenger Lectures 1934 (1947), p. 211.

Ce n'est point l'observation mais la théorie qui m'a conduit à ce résultat que l'expérience a ensuite confirmé.
explaining how he was led to discover the law characterizing interference fringes, in [Œuvres complètes d'Augustin Fresnel, Imprimerie impériale, 1866, http://books.google.com/books?id=3QgAAAAAMAAJ, 61]

Introduction, A New Gravity Theory, p. xi
Reinventing Gravity (2008)

Source: A Brief History of Time (1988), Ch. 1
Context: Any physical theory is always provisional, in the sense that it is only a hypothesis: you can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory by finding even a single observation that disagrees with the predictions of the theory. As philosopher of science Karl Popper has emphasized, a good theory is characterized by the fact that it makes a number of predictions that could in principle be disproved or falsified by observation. Each time new experiments are observed to agree with the predictions the theory survives, and our confidence in it is increased; but if ever a new observation is found to disagree, we have to abandon or modify the theory.

During a debate with Roger Penrose in 1994 at the Isaac Newton Institute for Mathematical Sciences at the University of Cambridge, transcribed in The Nature of Space and Time (1996) by Stephen Hawking and Roger Penrose, p. 121 http://books.google.com/books?id=LstaQTXP65cC&lpg=PP1&dq=nature%20of%20space%20and%20time&pg=PA121#v=onepage&q=&f=false

"Matter" in Man's Right to Knowledge, 2nd series (1954), p. 10; also in Writings on Physics and Philosophy‎ (1994) edited by Charles Paul P. Enz and Karl von Meyenn
Context: In the new pattern of thought we do not assume any longer the detached observer, occurring in the idealizations of this classical type of theory, but an observer who by his indeterminable effects creates a new situation, theoretically described as a new state of the observed system. In this way every observation is a singling out of a particular factual result, here and now, from the theoretical possibilities, therefore making obvious the discontinuous aspect of physical phenomena.
Nevertheless, there remains still in the new kind of theory an objective reality, inasmuch as these theories deny any possibility for the observer to influence the result of a measurement, once the experimental arrangement is chosen. Therefore particular qualities of an individual observer do not enter into the conceptual framework of the theory.

Source: Evolution: A Theory in Crisis (1986), p. 75