theoretical physicists are soooooo dreamy

werner heisenberg, from science as a means of international understanding, delivered at göttingen university on july 13, 1946:

At the end of the Middle Ages man discovered, apart from the Christian reality centred round the divine revelation, yet another reality of material experience. That was "objective" reality which we experience through our senses or by experiment. But in this advance into a new field certain methods of thought remained unchanged. Nature consisted of things in space which changed in time according to cause and effect. Outside of this there was the world of spirit, that is, the reality of one's own mind which reflected the external world like a more or less perfect mirror. Much as the reality determined by the sciences differed from the Christian reality, it nevertheless represented also a divine world order with man's action based on a firm foundation, and in which there could be little doubt about the purpose of life. . . .

But this view of nature has also become undermined during our century. Fundamental attitudes of thought lost their absolute importance as concrete action moved more and more into the centre of our world. Even time and space became a subject of experience and lost their symbolic content. In science we realize more and more that our understanding of nature cannot begin with some definite cognition, that it cannot be built upon such a rock-like foundation, but that all cognition is, so to speak, suspended over an unfathomable depth.

. . . In those branches of science in which we have found that our knowledge is "suspended in mid-air," in just those branches, have we achieved a crystal-clear understanding of the relevant phenomena… We can rest assured that there will be a final decision as to what is right and what is wrong. This decision will not depend on the belief, race or origin of the scientists, but it will be taken by a higher power and will then apply to all men for all time. While we cannot avoid in political life a constant change of values, a struggle of one set of illusions and misleading ideas against another set of illusions and equally misleading ideas, there will always be a "right or wrong" in science. There is a higher power, not influenced by our wishes, which finally decides and judges. The core of science is formed, to my mind, by the pure sciences, which are not concerned with practical applications. They are the branches in which pure thought attempts to discover the hidden harmonies of nature. Mankind today may find this innermost circle in which science and art can hardly be separated, in which the personification of pure truth is no longer disguised by human ideologies and desires.

. . . Science can contribute to the understanding between peoples. It can do so not because it can render succour to the sick, nor because of the terror which some political power may wield with its aid, but only by turning our attention to that "centre" which can establish order in the world at large, perhaps simply to the fact that the world is beautiful. . . . Take from your scientific work a serious and incorruptible method of thought, help to spread it, because no understanding is possible without it. Revere those things beyond science which really matter and about which it is so difficult to speak.