In 1969 Werner Heisenberg published an autobiographical book called “Der Teil und das Ganze”, a title meaning „The parts and the whole“. The book is partially an autobiography, partially a collection of philosophical dialogs in the tradition of Plato, based on conversations Heisenberg had with several other people, like, for example Niels Bohr, Wolfgang Pauli or Albert Einstein, exploring the border zone between physics and philosophy. The book is interesting and I recommend reading it, but I disagree with Heisenberg on certain views expressed in it. Before describing my objections, let me briefly sketch Heisenberg’s views, as I understand them. The two – closely interconnected – topics I am dealing with here are the role of beauty in science and the question why nature is understandable by the human mind.
The role of beauty in science is one of the recurring themes of the book. In the fifth chapter of the book Heisenberg describes the discovery of quantum mechanics during a stay on the island of Helgoland:
At the first moment I was deeply shocked. I had the feeling to look through the surface of atomic phenomena down to a ground of strange inner beauty lying deep beneath it and I nearly got dizzy from thinking that I should now go into the matter of investigating this abundance of mathematical structures nature had spread down there in front of me.
A few pages later, where he reports a discussion with Einstein, Heisenberg, referring to laws of nature, writes about “Forms of great simplicity and beauty” (“Formen von großer Einfachheit und Schönheit”).
Reading the book, it becomes clear that Heisenberg operates here within a platonic concept of beauty. In a talk entitled “Die Bedeutung des Schönen in der exakten Naturwissenschaft“, he explicitly discusses the role of the concept of beauty in ancient Greek philosophy of nature and in the works of Plato. Here he also refers to a definition of beauty derived from Neo-Platonism, where beauty is defined as the agreement of the parts with the whole. It looks like this has provided the motivation for the original German title of the autobiographical book, so it seems to have been very significant for Heisenberg. In the conclusion of that talk he writes:
But in the moment when the right idea appears, a totally ineffable process of highest intensity takes place in the soul of the person seeing it. It is the astonished shock about which Plato is talking in the ‘Phaedrus’, by which the soul in a way remembers something that unconsciously it always possessed already.
This refers to the Platonic concept of anamnesis according to which knowledge is gained through a process of remembering the forms already known. It looks like this idea had a strong influence of Heisenberg. He also discusses it in another article in the same collection where he describes the philosophical views of his friend, the physicist Wolfgang Pauli. Pauli was a friend of the psychologists C.G. Jung and referred to Jung’s concept of “archetypes” as well as writings of Johannes Kepler. Kepler also uses the term “archetypus” in a similar meaning. All these conceptions can be viewed as forms of Platonism.
The question of how it is possible that we are able to understand the laws underlying the world is answered by Heisenberg in this platonic context. In chapter 8 of “Der Teil und das Ganze”, he writes:
But with respect to nature, I firmly believed that its structures were after all simple; it was my conviction that nature is structured in a way that it can be understood. Or maybe I should more correctly say it the other way around: that our faculty of thought is structured in a way that it can understand nature. […] The organizing forces that gave rise to nature in all its forms are the same ones that are responsible for the structure of our soul and thus of our faculty of thought”.
This idea, that nature is understandable because our understanding was formed by the same forces that formed nature, is connected to those concepts of anamnesis and of archetypes.
Now, what do I think about Heisenberg’s ideas? First of all, as I have explained in several articles on my Blog Creativistic Philosophy, I think that there is no such thing at all as a fixed structure of our faculty of thought, and I think this is exactly the reason why we are actually able to understand the world. The tradition that goes from Plato and Kepler to Pauli and Heisenberg (and also Kant) is that our thinking and perception has a fixed structure that is a precondition for the possibility of acquiring knowledge.
Instead, my conviction is that the mind is a creative system capable of extending itself by incorporating information from the world. There are no a priory structures, no archetypes or pre-viewed platonic forms. Instead, the mind has a limitless plasticity, an ability to develop out of any limited framework. If there are innate structures at all, they are probably simple and not very sophisticated and they only form the starting point of development and modification, a scaffold on which the knowledge is erected and which may then be broken down.
In Heisenberg’s view, the platonic view of knowledge is closely connected to the platonic concept of beauty. Here I also disagree with him. Beauty, I think, is an emotion rewarding a successful unification, a discovery of order (see On Beauty). This refers to the discovery of order in perception as well as to the discovery of order in scientific data. Beauty is not a property of the thing we find beautiful, it is also not a form in a platonic realm of abstract forms, it is a property or consequence of the cognitive process. When Heisenberg managed to unify a lot of single results in a single framework of what became known as quantum mechanics, he was rewarded with a strong feeling of beauty. The same happened to Kepler when he discovered regularity in the motions of the planets. Both of them interpreted this in the context of the ultimately platonic theory of beauty and truth that was available to them. Both of them seem to have believed in some version of the platonic anamnesis theory. And in this, I think, both of them where wrong. Beauty does indeed play an important role in processes of discovery, but, I think, for different reasons than Heisenberg thought.
No a priori structure of the mind is the condition for the possibility of knowledge, but the absence of such a fixed structure. No algorithm can discover every instance of order. The mind is universal because it is not an algorithm. It is a creative system. If order could be discovered by an algorithm, a reward for its discovery – and that is what I think the feeling of beauty is – would not be necessary. Beauty is involved in discovery because the mind and thus the process of discovery has no fixed form.
 An English translation has been published as “Physics and Beyond”. Since this translation is not available to me at the moment, the citations are my own translations. The meaning of the original German title is “The Part and the Whole”.
 „Im ersten Augenblick war ich zutiefst erschrocken. Ich hatte das Gefühl, durch die Oberfläche der atomaren Erscheinungen hindurch auf einen tief darunter liegendn Grund von merkwürdiger innerer Schönheit zu schauen, ue es wurde mir fast schwindelig bei dem Gedanken, daß ich nun dieser Fülle von mathematischen Strukturen nachgehen sollte, die die Natur dort unten vor mir ausgebreitet hatte.“
 „Die Bedeutung des Schönen in der exakten Naturwissenschaft. In Heisenberg, Werner: Schritte über Grenzen, 2. erweiterte Auflage, Piper & Co. Verlag, München 1973, p.288 – 305.
The German title of this book means „steps across borders“.
 „In dem Moment aber, in dem die richtigen Ideen auftauchen, spielt sich in der Seele dessen, der sie sieht, ein ganz unbeschreiblicher Vorgang von höchster Intensität ab. Es ist das staunende Erschrecken, von dem Platon im ‚Phaidros‘ spricht, mit dem die Seele sich gleichsam an etwas zurückerinnert, was sie unbewusst doch immer schon besessen hatte.”
 In: „Schritte über Grenzen“ (see Footnote 3), p. 43 – 51.
 „Bei der Natur aber glaubte ich fest daran, dass ihre Zusammenhänge letzten Endes einfach seien; die Natur ist, das war meine Überzeugung, so gemacht, dass sie verstanden werden kann. Oder vielleicht sollte ich richtiger umgekehrt sagen, unser Denkvermögen ist so gemacht, dass es die Natur verstehen kann. … Es sind die gleichen ordnenden Kräfte, die die Natur in allen ihren Formen gebildet haben und die für die Struktur unserer Seele, also auch unseres Denkvermögens verantwortlich sind.