“… this is, precisely, the greatest mischief of recent physics, that experiments have been, as it were, segregated from man, and that one only wants to recognize nature in what artificial instruments show, in this way even limit and prove what it can achieve. It is the same with calculation. There is much that is true which cannot be calculated, as well as much that cannot be brought to the point of decisive experiment.”

J.W. von Goethe, Wilhelm Meister’s Journeyman Years. , S.397

“The most dangerous of all worldviews is the worldview of those people who have not looked at the world.” (Attributed to Humboldt)

„The world offers itself to us as a series of changing and colorful images that seem to follow one another capriciously. All physicists know that these fugitive aspects cover an unchanging background; but not all know how to discover it. Some, like the child who pursues a butterfly, are attached to the ephemeral aspects of the phenomenon, without discerning what it has in common with what precedes and follows; others seem to look only into their own thoughts and close their eyes when nature ventures to contradict them. True physicists, like Curie, look neither within themselves nor at the surface of things; they know how to see beneath things.“

Henri Poincaré, Eulogy of Pierre Curie at the Académie des Sciences, 1906

“These pictures,” Bohr replied, “are derived from experience, or, if you like, guessed, not from any theoretical calculations. I hope that these pictures describe the structure of the atoms as well, but only as well, as is possible in the descriptive language of classical physics. We must be clear about the fact that language can only be used here in a similar way as in poetry, which is not about precisely representing facts, but about creating images in the listener’s consciousness and establishing mental connections.”

Quoted by Werner Heisenberg in Physics and Beyond – Encounters and Conversations: , p. 41. Translated from the German by Arnold J. Pomerans. Harper & Row Publishers. S.63. Piper Verlag, München.

“… in my opinion it is only a narrow path of truth (be it a scientific or some other truth) that passes between the Scylla of a blue haze of mysticism and the Charybdis of a sterile rationalism. This path will always be full of traps, and one can fall on either side. Thus, people who pretend to be pure rationalists and are prone to call the others “mystics” are always suspect to me of having fallen somewhere into quite primitive superstition.”

Wolfgang Pauli, Letter to Viktor Weisskopf from 8th February 1954, in Scientific Correspondence with Bohr, Einstein, Heisenberg a.o., Volume IV, Part II, 1953-1954, [Letter 1716], p. 465-466. Springer.

“In a second work, Einstein took up the investigations of the Dutch physicist Lorentz about the electrodynamics of moving bodies. At that point, the American physicist Michelson had first demonstrated in 1902 through his famous interference experiment that the movement of the earth in space – or, as was said then, relative to the ether – is not noticeable in optical experiments. Based on a mathematic analysis of the situation created by Michelson’s experiment, Lorentz then developed certain transformation formulae in 1904, the so-called “Lorentz transformation”, from which he concluded that moving bodies appear in a certain way to shorten in the direction of movement and that moving clocks indicate an apparent time that runs more slowly than the real time. Under these conditions, Lorentz was able to interpret Michelson’s result, but Lorentz’s formulae seemed physically incomprehensible, and therefore unsatisfactory. This is where Einstein intervened and solved all the difficulties with a magic stroke. He assumed that the bodies really do shorten in the direction of movement and that the apparent time of the Lorentz formulae is already the true time; that these formulae therefore conveyed a new insight into space and time itself. Thus, the foundation of the theory of relativity was laid”.

Werner Heisenberg: „Albert Einstein’s Scientific Work“ – „Albert Einsteins wissenschaftliches Werk“ (1955), Gesammelte Werke C IV, p. 91. Piper.

“If one asks what the great achievement of Christopher Columbus was when he discovered America, one will have to answer that it was not the idea of taking advantage of the spherical shape of the earth to travel to India by the western route; this idea had already been considered by others. Nor was it the meticulous preparation of his expedition, the expert equipping of the ships, that, too, others could have done equally well. But the hardest part of this voyage of discovery was surely the decision to leave all known land and to sail west so far that it was no longer possible to turn back with the supplies available.
In a similar way, truly new territory in a science can probably only be won if one is prepared at a decisive point to leave the ground on which the previous science rests and, as it were, to jump into the void. In his theory of relativity, Einstein had abandoned that concept of simultaneity which had been one of the firm foundations of earlier physics, and it was precisely this abandonment of the earlier concept of simultaneity, which many physicists and philosophers, even eminent ones, were unable to complete, that made them bitter opponents of the theory of relativity. It can perhaps be said that the progress of science generally only requires those involved in it to absorb and process new thought content; those active in science are almost always prepared to do this. However, when truly new territory is entered, it can happen that not only new contents have to be absorbed, but that the structure of thinking has to change if one wants to understand the new. Obviously, many are not willing or able to do this.”

Werner Heisenberg, The Part and the Whole (known as “Physics and Beyond – Encounters and Conversations”).

The pack of devils by no rules is daunted:
We are so wise, and yet is Tegel haunted.

Faust, Translation Bayard Taylor. Houghton Mifflin Company. 1870

There was at Athens a large and spacious, but ill‑reputed and pestilential house. In the dead of the night a noise, resembling the clashing of iron, was frequently heard, which, if you listened more attentively, sounded like the rattling of fetters; at first it seemed at a distance, but approached nearer by degrees; immediately afterward a phantom appeared in the form of an old man, extremely meagre and squalid, with a long beard and bristling hair; rattling the gyves on his feet and hands. The poor inhabitants consequently passed sleepless nights under the most dismal terrors imaginable. This, as it broke their rest, threw them into distempers, which, as their horrors of mind increased, proved in the end fatal to their lives. For even in the day time, though the spectre did not appear, yet the remembrance of it made such a strong impression on their imaginations that it still seemed before their eyes, and their terror remained when the cause of it was gone. By this means the house was at last deserted, as being judged by everybody to be absolutely uninhabitable; so that it was now entirely abandoned to the ghost. However, in hopes that some tenant might be found who was ignorant of this great calamity which attended it, a bill was put up, giving notice that it was either to be let or sold.

It happened that Athenodorus the philosopher came to Athens at this time, and reading the bill ascertained the price. The extraordinary cheapness raised his suspicion; nevertheless, when he heard the whole story, he was so far from being discouraged, that he was more strongly inclined to hire it, and, in short, actually did so. When it grew towards evening, he ordered a couch to be prepared for him in the fore‑part of the house, and after calling for a light, together with his pen and tablets, he directed all his people to retire within. But that his mind might not, for want of employment, be open to the vain terrors of imaginary noises and apparitions, he applied himself to writing with all his faculties. The first part of the night passed with usual silence, then began the clanking of iron fetters; however, he neither lifted up his eyes, nor laid down his pen, but closed his ears by concentrating his attention. The noise increased and advanced nearer, till it seemed at the door, and at last in the chamber. He looked round and saw the apparition exactly as it had been described to him: it stood before him, beckoning with the finger. Athenodorus made a sign with his hand that it should wait a little, and bent again to his writing, but the ghost rattling its chains over his head as he wrote, he looked round and saw it beckoning as before. Upon this he immediately took up his lamp and followed it. The ghost slowly stalked along, as if encumbered with its chains; and having turned into the courtyard of the house, suddenly vanished. Athenodorus being thus deserted, marked the spot with a handful of grass and leaves. The next day he went to the magistrates, and advised them to order that spot to be dug up. There they found bones commingled and intertwined with chains; for the body had mouldered away by long Iying in the ground, leaving them bare, and corroded by the fetters. The bones were collected, and buried at the public expense; and after the ghost was thus duly laid the house was haunted no more.

Pliny the Younger, Letter to Sura, Book 7, letter 27, in Letters, Volume I: Books 1-7. Translated by William Melmoth, 1746. Loeb classical libra

“[Gödel] said that some imp was in the house. […] Gödel insinuated that there was an invisible force that prevented him from finding this article. […] Karl (Morgenstern) knew that Gödel was interested in these things, but Gödel naturally did not want to discuss them with people he thought would disagree with him or who would not be receptive to them.”

Wahrheit und Beweisbarkeit, , T. Ip. 252

“We might, e.g., possess an additional sense that would show to us a second reality completely separated from space-time reality and moreover so regular that it could be described by a finite number of laws. […] I believe that this approaches the real situation, except that reason is not counted with the senses because its objects are quite different from those of the other senses.”

Collected Works, 1953/1959, T. III, p. 353

Gödel is convinced that the human brain is a Turing machine. Thus, if the human mind surpasses any Turing machine, its functioning is irreducible to the brain mechanism and reveals another reality, a kind of soul, itself irreducible to the sensible world. It is, finally, in this result that Gödel summarizes the incompleteness theorem, the impossibility of doing without a non-material object.

“My theorems only show that the mechanization of mathematics, i.e. the elimination of the mind and of abstract entities, is impossible, if one wants to have a satisfactory foundation and system of mathematics.”

To Leon Rappaport, 1962, Collected Works, T. V, p. 176, quoted by Pierre Cassou-Noguès in Les démons de Gödel, p.110. Éditions du Seuil.

“Today, of course, we are far from being able to justify the theological world view scientifically, but I believe that even today it should be possible to see purely rationally (without relying on faith and any religion) that the theological world view is entirely compatible with all known facts (including the conditions that prevail on our earth). This is what the famous philosopher and mathematician (Leibniz) tried to do 250 years ago, and this is also what I have tried to do in my last letters. What I call theological worldview is the idea that the world and everything in it has sense and reason, namely a good and undoubted sense. From this follows directly that our existence on earth, since it has at most a very doubtful sense, can only be a means to an end for another existence. The idea that everything in the world has a sense is, by the way, exactly analogous to the principle that everything has a cause, on which the whole science is based.”

Letter to Marianne Gödel, October 6th, 1961, Collected Works, T. IV, p. 439

“The ingenuity, the penetration, the patience, the tenacity you have shown in the exploration of the terra incognita of psychical phenomena have always appeared to me truly admirable. But still more than the ingenuity and the penetration, still more than the unwearying perseverance with which you have continued your course, I admire the courage which it has required, especially during the first years, to struggle against the prejudices of a great part of the scientific world, and to brave the mockery which strikes fear into the boldest breast.
How are we to explain the prejudice there always has been, and still is, against psychical science? True, it is more often the smatterer than the scientist who takes upon himself to condemn your researches “in the name of Science.” Physicists, chemists, physiologists, physicians belong to your society, and beside these there are an increasing number of men of science who, without belonging to you, are interested in the work you are doing. Yet it is none the less true that there are scientific workers of repute, men ready to welcome any laboratory work, however restricted and minute it be, who yet dismiss with a foregone conclusion what you bring forward and reject outright all you have done.
It seems to me that in philosophy the time given up to refutation is generally time lost. Of the many objections raised by so many thinkers against one another, what remains? Nothing, or next to nothing. That which counts, that which lasts, is the positive truth we bring out; the true idea pushes out the false one by its mere weight and thus proves to be, without our refuting anybody, the best of refutations. But quite another thing is here in question than either refuting or criticizing. I want to show that behind the prejudices of some, the mockery of others, there is, present and invisible, a certain metaphysic unconscious of itself, – unconscious and therefore inconsistent, unconscious and therefore incapable of continually remodeling itself on observation and experience as every philosophy worthy of the name must do, – that, moreover, this metaphysics is natural, due at any rate to a bent contracted long ago by the human mind, and that this explains its persistence and popularity.
There is nothing more displeasing to the professional student than to see introduced into a science of the same order as his own, methods of research and verification from which he has himself always carefully abstained. He fears the contagion. Quite legitimately, he holds to his method as the workman to his tools. He loves it for itself, and not only for what it does. It was William James, I think, who defined the difference between the professional and the amateur by saying that the latter interests himself especially in the result obtained, the former in the way in which he obtains it. Well, the phenomena with which you are occupied are undeniably of the same kind as those which form the subject-matter of natural science, whilst the method you follow, and are obliged to follow, has often no relation to that of the natural sciences.
…. a veridical hallucination, – the apparition, for instance, of a sick or dying man to a relation or friend far away, it may be at the antipodes, – is a fact which, if it be real, is unquestionably the manifestation of a law analogous to physical, chemical and biological laws.”

“Fantômes de Vivants” et “Recherche Psychique”.
Lecture given on May 28th, 1913 to the Society for psychical Research in London. Eigene Übersetzung.

Henri Bergson, Mind-Energy – Lectures and Essays, p. 75-79.
Translation H. Wildon Carr. Henry Holt and Co. 1920.