Primas' 2009 article, "Complementary of Mind and Matter," is an exegesis of what may have been Pauli's thoughts on psyche and physis - mind and matter.

1 Introduction: Pauli on Mind and Matter

At the end of his authoritative article The Influence of Archetypal Ideas on the Scientific Theories of Kepler Wolfgang Pauli (1952, p. 164) stated:

"The general problem of the relation between psyche and physis, between inside and outside, can hardly be regarded as solved by the term 'psychophysical parallelism' advanced in the last century."

He continued with the visionary remark:

"It would be most satisfactory of all if physis and psyche could be seen as complementary aspects of the same reality." Neither in Pauli's publications nor in his letters we can find an elaboration of or more details about this idea. Consequently, I will not give an exegesis of Pauli's writings, but use them just as a source of inspiration. First of all, we are confronted with the following four nontrivial question:

1. How can we characterize "physis"?
2. How can we characterize "psyche"?
3. What do we mean by "complementarity aspects"?
4. What do we mean by "the same reality"?

These questions are not yet well-defined - there are many possible answers. In the following I propose a scenario in which Pauli's vision can be discussed consistently in simple and mathematically well-defined terms which allow us to work out additional details. Thereby I adopt an ontological monism, combined with an epistemic symmetry breaking leading to an epistemic dual-aspect approach. The dual aspects refer to tenseless descriptions in terms of a homogeneous time and to tensed descriptions in terms of a non-homogeneous time characterized by a privileged instant, the Now.

2 The First Problem: What is Matter?

2.1 Pauli's Answer

Even the answer to the apparently easy question "what is matter?" has changed dramatically several times since 1644, when Descartes classified matter and mind as distinct substances. At any rate, the traditional characterization of the physical as res extensa and of the mental as res cogitans does not allow to construct a workable theory for the mind-matter problem.

Similarly we cannot adopt atomism, which was the starting point of historical classical science: the idea that there exist theory-independent elementary objects, for example in the sense of Newton:

"God in the Beginning form'd Matter in solid,
massy, hard, impenetrable moveable Particles".

Today nobody defends Newton's atomistic ontology any more. Nevertheless, the naive reductionism which tries to explain all phenomena in terms of entities at a supposedly lowest level of theoretical description is still popular. This approach fails simply because the presumed lower level entities do not exist in a theory-independent sense.

We replace the vague "patterns of reality" with the more concrete "information structures"

Modern quantum mechanics put an end to atomism. The so-called "fundamental" entities (such as electrons, quarks, or gluons) represent patterns of reality, yet they are not building blocks of reality. They are not primary, but rather secondary and derived, in the same sense as solitons are localized excitations of water, and not building blocks of water.

There is a bewildering diversity of concepts of matter. Certainly no substantial advance in the mind-matter problem can be achieved without a clear characterization of what we mean by matter. Fortunately we can find a modern answer to the question What is Matter? in Pauli's (1954) contribution to the International Symposium Presented in Honor of the Two-Hundredth Anniversary of Columbia University:

"Matter has always been and will always be one of the main objects of physics. . . . even light has become matter now, due to Einstein's discoveries. It has mass and also weight; it is not different from ordinary matter, it too having both energy and momentum."
"Taking the existence of all these transmutations into account, what remains of the old ideas of matter and substance? The answer is energy. This is the true substance, that which is conserved; only the form in which it appears is changing."

2.2 Matter and Homogeneous Time

Adopting Pauli's answer, we have to recall that energy conservation is subject to a fundamental theorem by Emmy Noether (1918) which provides a deep connection between symmetries and conservation laws: For every conservation law, there exists a continuous symmetry. By definition, energy is the conserved quantity related to the time-translation symmetry. The concept of energy is meaningless if time is not homogeneous. In other words, energy conservation holds only if the presupposed equations of motion do not contain any preferred moment of time.

3 The Second Problem:
How to Characterize the Mental Domain?

3.1 Violation of Physical Laws?

A recurrent theme in discussions of the mind-matter problem is the alleged violation of physical laws - usually without giving a precise account how we have to understand a "physical law". Yet, the scope of validity of conservation laws is well understood: a conservation law holds if and only if the system considered is invariant under the corresponding Noether-symmetry operation. Therefore it makes no sense to argue as Bunge (1980, p. 17) does:

"If immaterial mind could move matter, then it would create energy; and if matter were to act on immaterial mind, then energy would disappear. In either case energy . . . would fail to be conserved. And so physics, chemistry, biology, and economics would collapse."

Intentional influences are not invariant under time-translations, so that in this case any argument involving energy conservation is misplaced. Whenever energy is well-defined, it is conserved by definition. Therefore it makes no sense to speak of the violation of energy conservation.

3.2 The Physical World is Not Causally Closed

Physicalism as a doctrine about the empirical world, claiming "that mental entities, properties, relations and facts are all really physical". Or in another formulation: "Physics can, in principle, predict the probability with which a human body will follow any given trajectory" (Putnam, 1992, p. 83). Many philosophers assume a metaphysical naturalism, claiming that the realm of the physical is "causally closed". In the weakest conception, causal closure means that "every physical phenomenon that has a sufficient cause has a sufficient physical cause". According to Kim (1980, p. 40) another way of stating the principle of physical causal closure is this:

"If you pick any physical event and trace out its causal ancestry or posterity, that will never take you outside the physical domain. . . . If you reject this principle, you are ipso facto rejecting the in-principle completability of physics."

This argument is incorrect for the simple reason of quantum indeterminacy. The determinism of relativity is irrelevant.

This argument is not correct. It is true that under very general conditions any causally open physical system can be embedded into a causally closed time-invariant description with a larger state space. However, such an ad hoc extension presupposes a two-way determinism, where the present is "mathematically determined jointly by the past and future, however remote". That is, only if the external influences are given for all past and future times, then we can reconstruct a local time-invariant deterministic description. Even if we can reconstruct a causal ancestry (which is by no means unique) in every particular case, this does not imply the possibility of a global causal reconstruction.

The assertion that "modern science is premised on the assumption that the material world is a causally closed system" is in striking contradiction to experimental science. Every experiment requires an irreversible dynamics. No experiment refers to a closed physical system. In a strictly deterministic world it would neither be possible to perform meaningful experiments nor to verify the partially causal behavior of a physical system. We conclude that science neither assumes that the material world is a causally closed system, nor that physical laws imply the causal closure of physics.

3.3 Experimental Physics Requires Intentionality

All experimental science is based on the understanding that the actions of an experimenter are intentional, and not actions which happen to him. There are no physical laws which cover intentionality (understood as the mind's directedness upon objects).

Free choice as to which experiment to do is defended even by determinists like Einstein, who saw physical theories as the "free creations of the human mind."

Experimental physics demands the distinction of past and future, the concept of the now, and the freedom of the experimenter to choose initial conditions. To test experimentally whether a given physical system is causal, it is indispensable that the experimenter has the freedom to deliberately choose (within well-defined limits) a stimulus and then to record the response. Moreover, it is required that an experiment can be repeated at any particular instant.

Sometimes it is claimed that such a freedom is illusory. Yet, without this freedom all experimental science would be pointless:

To deny the freedom of action of an experimenter
is to deny the meaningfulness of experimental science.

Every experimental investigation presupposes that the specific design and implementation of an experiment is compatible with, but not exclusively determined by, known physical laws. This situation does not imply that the first principles of physics are inconsistent or not valid, but only that they cannot account for intentionally chosen experimental arrangements and initial conditions. This fact "proves that contingency is an essential feature of the world".

("Complementarity of Mind and Matter," in Recasting Reality, Springer, 2009, pp.171-5)

Primas' description of Jung's three domains suggests they are fundamentally informational, thus we can argue for a triple-aspect monism.

5 The Fourth Problem:
How to Characterize the "Unus Mundus"?

5.1 A Model of a Holistic Universe of Discourse.

For convenience but without loss of generality we divide the universe into three mutually compatible parts recognized as a mental domain, a material domain, and an interface between these domains.

("Complementarity of Mind and Matter," in Recasting Reality, p.178-9)