There is not the slightest doubt that Heisenberg’s interpretation of quantum physics was heavily influenced by his philosophical views. Even as a student, Heisenberg was a conscious idealist, who admits being greatly impressed by Plato’s Timaeus (where Plato’s idealism is expressed in the most obscurantist way), while fighting in the ranks of the reactionary Freikorps against the German workers in 1919. Subsequently he stated that he was “much more interested in the underlying philosophical ideas than in the rest”, and that it was necessary “to get away from the idea of objective processes in time and space”. In other words, Heisenberg’s philosophical interpretation of quantum physics was very far from being the objective result of scientific experiment. It was clearly linked to idealist philosophy, which he consciously applied to physics, and which determined his outlook.

Such a philosophy is at odds not only with science, but the whole of human experience. Not only does it lack any scientific content, but it turns out to be perfectly useless in practice. Scientists who, as a rule, like to steer clear of philosophical speculation, make a polite nod in the direction of Heisenberg, and simply get on with the job of investigating the laws of nature, taking for granted not only that it exists, but that it functions according to definite laws, including those of cause and effect, and that, with a bit of effort, can be perfectly well understood, and even predicted by men and women. The reactionary consequences of this subjective idealism are shown by Heisenberg’s own evolution. He justified his active collaboration with the Nazis on the grounds that “There are no general guidelines to which we can cling. We have to decide for ourselves, and cannot tell in advance if we are doing right or wrong.”[8]

Erwin Schrödinger did not deny the existence of random phenomena in nature in general or in quantum mechanics. He specifically mentions the example of the random combining of DNA molecules at the moment of conception of a child, in which the quantum features of the chemical bond play a role. However, he objected to the standard Copenhagen interpretation about the implications of the “two-hole” experiment; that Max Born’s waves of probability meant that we had to renounce the objectivity of the world, the idea that the world exists independently of our observing it.

Schrödinger ridiculed the assertion of Heisenberg and Bohr that, when an electron or photon is not being observed, it has “no position” and only materialises at a given point as a result of the observation. To counter it, he devised a famous “thought experiment”. Take a cat and put it in a box with a vial of cyanide, he said. When a Geiger counter detects the decay of an atom, the vial is broken. According to Heisenberg, the atom does not “know” it has decayed until someone measures it. In this case, therefore, until someone opens the box and looks in, according to the idealists, the cat is neither dead nor alive! By this anecdote, Schrödinger meant to highlight the absurd contradictions caused by the acceptance of Heisenberg’s subjective idealist interpretation of quantum physics. The processes of nature take place objectively, irrespective of whether human beings are around to observe them or not.

According to the Copenhagen interpretation, reality only comes into being when we observe it. Otherwise, it exists in a kind of limbo, or “probability wave superposition state”, like our live-and-dead cat. The Copenhagen interpretation draws a sharp line of distinction between the observer and the observed. Some physicists take the view, following the Copenhagen interpretation, that consciousness must exist, but the idea of material reality without consciousness is unthinkable. This is precisely the standpoint of subjective idealism, which Lenin comprehensively answered in his book Materialism and Empirio-criticism.

Dialectical materialism sets out from the objectivity of the material universe, which is given to us through sense perception. “I interpret the world through my senses.” That is self-evident. But the world exists independently of my senses. That is also self-evident, one might think, but not for modern bourgeois philosophy! One of the main strands of 20th century philosophy is logical positivism, which precisely denies the objectivity of the material world. More correctly, it considers that the very question of whether the world exists or not to be irrelevant and “metaphysical”. The standpoint of subjective idealism has been completely undermined by the discoveries of 20th century science. The act of observation means that our eyes are receiving energy from an external source in the form of light waves (photons). This was clearly explained by Lenin in 1908-09:

If colour is a sensation only depending upon the retina (as natural science compels you to admit), then light rays, falling upon the retina, produce the sensation of colour. This means that outside us, independently of us and of our minds, there exists a movement of matter, let us say of ether waves of a definite length and of a definite velocity, which, acting upon the retina, produce the sensation of colour. This is precisely how natural science regards it. It explains the sensations of various colours by the various lengths of light waves existing outside the human retina, outside man and independently of him. This is materialism: matter acting upon our sense organs produces sensation. Sensation depends on the brain, nerves, retina, etc., i.e., on matter organised in a definite way. The existence of matter does not depend on sensation. Matter is primary. Sensation, thought, consciousness are the supreme product of matter organised in a particular way. Such are the views of materialism in general, and of Marx and Engels in particular.[9]

The subjective idealist nature of Heisenberg’s method is quite explicit:

Our actual situation in research work in atomic physics is usually this: we wish to understand a certain phenomenon, we wish to recognise how this phenomenon follows from the general laws of nature. Therefore, that part of matter or radiation that takes part in the phenomenon is the natural ‘object’ in the theoretical treatment and should be separated in this respect from the tools used to study the phenomenon. This again emphasises a subjective element in the description of atomic events, since the measuring device has been constructed by the observer, and we have to remember that what we observe is not nature in itself but nature exposed to our method of questioning. Our scientific work in physics consists in asking questions about nature in the language that we possess and trying to get an answer from experiment by the means that are at our disposal.[10]

Kant erected an impenetrable barrier between the world of appearances and reality “in itself”. Here Heisenberg goes one better. He not only speaks about “nature in itself”, but even maintains that we cannot really know that part of nature which can be observed, since we change it by the very act of observing it. In this way, Heisenberg seeks to abolish the criterion of scientific objectivity altogether. Unfortunately, many scientists who would indignantly deny the charge of mysticism have uncritically assimilated Heisenberg’s philosophical ideas, merely because they are unwilling to accept the necessity for a consistently materialist philosophical approach to nature.

The whole point is that the laws of formal logic break down beyond certain limits. This most certainly applies to the phenomena of the subatomic world, where the laws of identity, contradiction and the excluded middle cannot be applied. Heisenberg defends the standpoint of formal logic and idealism, and therefore, inevitably arrives at the conclusion that the contradictory phenomena at the subatomic level cannot be comprehended by human thought at all. The contradiction, however, is not in the observed phenomena at the subatomic level, but in the hopelessly antiquated and inadequate mental schema of formal logic. The so-called paradoxes of quantum mechanics are precisely this. Heisenberg cannot accept the existence of dialectical contradictions, and therefore prefers to revert to philosophical mysticism –”we cannot know”, and all the rest of it.

We find ourselves here in the presence of a kind of philosophical conjuring trick. The first step is to confuse the concept of causality with the old mechanical determinism represented by people like Laplace. These limitations were explained and criticised by Engels in the Dialectics of Nature. The discoveries of quantum mechanics finally destroyed the old mechanical determinism. The kind of predictions made by quantum mechanics is somewhat different from those of classical mechanics. Yet quantum mechanics still makes predictions, and obtains precise results from them.

  1. Lerner, E. The Big Bang Never Happened, pp. 362-3.

  2. LCW, Vol. 14, p. 55.

  3. Ferris, T. op. cit., pp. 95-6.