**The Role of Human Beings in the Quantum Universe**

[Henry P. Stapp]{.smallcaps}

*Lawrence Berkeley Laboratory, University of California, Berkeley
California 94720*

> A profound change in our scientific understanding of the role of human
> beings in the un­folding of our streams of conscious experiences was
> wrought by the twentieth century switch from classical mechanics to
> quantum mechanics. The streams of consciousness thoughts of human
> beings were converted from causally inert passive witnesses of the
> un­folding of a mechanically controlled and causally self-sufficient
> physical universe into logically needed dynamical inputs into the
> physical aspects of nature. These physical aspects, as they are now
> under­stood, contain causal gaps that are neatly filled by inputs from
> the realm of our conscious thoughts in a way that allows our conscious
> intentions to tend to produce their intended con­sequences.

[Keywords:]{.smallcaps} mind, brain, mental causation, quantum
mechanics, quantum collapse

**The Basic Question and Why It Is Important**

Science's conception of the physical world changed radically during the
twentieth cen­tu­ry, and the conception of the role of human beings in
that world changed in a closely co­ordinated way.

The scientific conception of the world that prevailed from the time of
Isaac Newton until the beginning of the twentieth century was that of a
giant machine. The world was im­agined to be fundamentally similar to a
huge clock, with its interlocking cogs and wheels grinding out with
mechanical precision the preordained unfolding of physical reality. The
physical bodies of human beings were therefore understood to be
mechanical automata, with our conscious intentional efforts considered
to be passive by-products of the complex activities of our brains. These
experiential aspects of reality were considered to be causally inert, in
the sense that they could produce no effects on the physically de­scribed
world -- beyond the effects entailed already by the purely physically
described con­nections acting alone.

Within that earlier pre-twentieth-century conception of nature the
existence of our streams of conscious thoughts constituted a major
embarrassment. The occurrence of things having the defining
characteristics of our conscious thoughts was in no way entailed by the
properties of the physical world that the physicists had postulated in
order to produce their causally closed theory of the physical world. Our
thoughts, ideas, and feelings could be imagined to be produced -- in
some unexplained way -- by the complex activities of our brains. But
there was no logical basis in the classical physicists' con­cep­tion of
nature for understanding or explaining the emergence of human
experience. Al­though philosophers wove endless tapestries of words in an
effort to relate the physically described aspects of the world to the
experientially felt aspects of our lives, the efforts of those thinkers
were invariably judged inadequate by their critically minded colleagues.
Insofar as our brains were understood in terms of the concepts of
classical physics a gap persisted. A chasm resisting rational closure
remained between, for example, a painful feeling and the corresponding
motions -- no matter how complex and novel -- of the phy­sically
described parts of the associated brain.

During the twentieth century this classical-physics-based conception of
the world was found to be logically incompatible with a growing
accumulation of empirical data. Even­tually, the classical mechanistic
description of the physical aspects of nature was replaced by a
profoundly different quantum mechanical description.

The orthodox formulation of quantum mechanics, which is the form used in
all practi­cal applications, was created by Heisenberg, Bohr, Pauli, and
Born during the 1920's. Shortly thereafter it was cast into a more
rigorous logical and mathematical form by the logician and mathematician
John von Neumann.

Quantum mechanics differs from classical mechanics in deep mathematical
ways. In order to tie the new mathematical structure to empirical data
in a practically useful way the founders of quantum mechanics instituted
a profound break with one of the basic principles of classical physics:
they inserted the conscious experiences of human beings into the
dynamical workings of the theory. Human beings were allowed, and indeed
re­quired, to act not merely as passive witnesses but also as causally
efficacious agents. Specifically, orthodox quantum mechanics requires
every observation to be preceded, logically, by an action that specifies
a 'Yes-or No' question, which a feedback "observa­tion" will immediately
answer either by a 'Yes' or by a 'No'. Both of the two actions, the
query and the feedback, are causally efficacious: they alter in
different non trivial ways the physically described state of the
universe. Each of these two actions is described in two different ways.
It is described first in the psychological language that we use to
com­municate to each other, and to ourselves, the structure of our
experiences. And this action is described also in the mathematical
language of quantum physics. Each psychologically described event
becomes thereby linked, *within the theory*, to the quan­tum mathematical
description of the physical world.

In this quantum mechanical description, the unfolding of the universe is
no longer governed exclusively by the physical aspects of the
description of nature. Neither of these two actions, neither the query
nor the feedback, is linked within the orthodox theory to some prior
physically described sufficient condition. In particular, within
orthodox quan­tum mechanics, our causally efficacious conscious
intentional efforts are free of any speci­­fied physical coercion.

But why are these seemingly arcane matters important? Why, in the
context of the major concerns of the human race, are these scientific
considerations pertinent?

They are important because science's pronouncements on the nature of our
own being, and on the character of the connection of our conscious
intentional efforts to the unfold­ing of the physical reality, underlie
much of the rational discourse on urgent socie­tal issues.

The classical-physics-based conception of human beings has had a highly
corrosive impact on societal matters because it paints us as, on the one
hand, mechanical automata, whose consciousness intentional efforts can
have no causal effects whatever on the phy­sically described aspects of
nature, and, on the other hand, as mechanical consequences of a
dog-eat-dog competition for survival. The consequence of the first
effect is to dis­courage effort as pointless and irrational; and the
consequence of the second effect is promote anti-social behavior
directed towards self-aggrandizement at the expense of the welfare of
others, and of other social and cultural groupings

Our beliefs about our relationship to the world around us underlie our
values, and our values determine the sort of world we strive to create.
The main social problems we face today stem primarily from the fact that
different approaches to this basic question of our own nature, and our
connection to the physically described world lead to different
conclusions, and hence to conflicting values, and consequently to
conflicting actions. Thus an important question is this:

What does basic physics -- namely quantum mechanics -- say about the
nature of the physically described world in which we are imbedded, and
about the connection of our thoughts, ideas, and feelings to that world?

**From the Classical to the Quantum Mechanical Conception of the Role of
Human Beings in the Unfolding of Reality**

Quantum mechanics rests upon a mathematical foundation provided by
classical mechan­ics. The latter rests upon the idea of 'particles' and
'fields'. A particle is supposed to have, at each instant of time, a
position and a velocity in three-dimensional space. A field is supposed
to have, at each instant of time and each location in three-dimensional
space, a 'value', specified by a real number. The field variables are
connected to the particle variables in way that allows one to compute
the forces upon -- and hence acceleration of --each particle due to the
presence and the motions of the other particles.

Newton conjectured the existence of repulsive forces that prevent
particles from coming too close to each other. This condition combined
with his other laws appears to entail 'causal closure of the physical':
the description of the physical aspects of the state of the universe at
one single time, or perhaps over some short interval of time, determines
the physical aspects of the state of the universe for all times.

This closure feature allows the evolving state of the universe to be
pictured as a block physical universe; namely by a collection of
infinitely thin 'wires' running through space-time, in the direction of
increasing time, and in a way that is uniquely determined for all times
by this physical structure at any single instant of time. (The 'fields'
should also be represented, but the pictorial image is slightly more
complicated.) No representa­tion of experience, or knowledge, or
experienced intent need be added, That is why this imagined property is
called 'causal closure of the physical.'

The transition from classical mechanics to quantum mechanics brought
human know­ledge and experience into the theoretical framework. The
reason, basically, is this: the way the mathematical/physical
description enters into practical applications is closely analogous to
the way that the mathematical/physical description enters into classical
*sta­tistical* mechanics. But classical statistical mechanics is, in
regard to its practical applica­tions, closely tied to human knowledge: A
sudden change in "our knowledge" causes, in classical statistical
mechanics, a sudden change in the mathematical/physical representa­tion
of our knowledge.

A key feature of quantum mechanics is the 'Heisenberg Uncertainty
Principle'. The effect of this principle is, essentially, to convert
each 'wire' of the block universe picture into a smear of possibilities.
More precisely, for a many-particle universe, it is to replace the one
single classical many-particle universe by the collection of all such
(weighted) possibilities compatible with the present state of "our
knowledge". Because of the sensi­tive dependence of macroscopic degrees
of freedom upon microscopic initial condi­tions, the diversity of this
population of possibilities tends to increase with the passage of time.
But from time to time we gain, via our (sense) experiences, new
knowledge. Just as in the case of classical statistical mechanics, this
new knowledge will usually exclude some of the possibilities that were
mathematically generated by the equations of motion acting upon the
mathematical representation of our prior knowledge. Thus the sudden gain
in knowledge will be coordinated to a sudden "collapse" of the
mathematical repre­sentation of our state of knowledge just before the
gain in knowledge to the 'reduced' state just after this gain in
knowledge. The physically described 'collapse' is thus a logi­cal
conse­quence of our increased knowledge.

There is nothing mysterious about such 'collapses' in classical
statistical mechanics, and the 'collapses' that occurs in quantum
mechanics are, at the level of actual scientific practice, analogous to
it: the mathematical representation of 'our knowledge' changes abruptly
when 'our knowledge' changes abruptly.

But there is a conceptual problem: the different 'classically conceived
possibilities' in­ter­fere with each other in a way that they cannot do in
classical statistical mechanics, but that would be understandable if the
mathematical representation of our knowledge de­scribed an objectively
real structure, instead of just an idea about a set of classically
con­ceivable possibilities.

The resolution of this conceptual problem is to interpret the
mathematically described state of the universe as a representation not
of just epistemic possibilities but rather of potentialities: i.e., as a
representation of objective tendencies, created by past psycho­phy­sical
events, for the occurrence of future psychophysical events. This
interpretation is essentially implicit in orthodox quantum mechanics.
This understanding places 'our knowledge' in a much more central, and
indeed, in a much more dynamical, position than what its place was in
classical mechanics.

Of course, science has always been about 'our knowledge' in a certain
ultimate way. It is about what we can know, and how we can use what we
know to affect what we will experience in the future. However, the
effect of Newton's monumental work was to push questions about knowledge
and our acquisition of knowledge out of the domain of the physical
sciences themselves: human knowledge and its acquisitions played no role
in causal structure of the physically described aspects of nature
envisaged in the conception of nature suggested by Newton's Principia.
The elevation of the 'phy­sically represented information' of classical
physics, whose causal structure is completely contained in the
self-sufficient physical descriptions, to the causally efficacious
'know­ledge' of quantum physics constitutes a radical break with
Newtonian-physics-based model of the rela­tionship between mind and
matter.

The main idea in quantum physics is that each acquisition of knowledge
occurs dis­cretely in conjunction with "a collapse of the quantum state"
to a new form that incor­porates the effect of adding the conditions
logically imposed by the increase in know­ledge. This change forges a
tight logical linkage between 'an experientially recognized change in a
state of knowledge' and a corresponding 'mathematically represented
change in the physical state of the universe'. The new physical state
represents, in quantum mechanics, not simply a new state of "our
knowledge," but also a new set of potentialities for future
psychophysical events.

**A Systematic Account**

**The "Classical" Approach is Materialism.**

Three key ideas of the classical physics of the late nineteenth century
are:

1\. There exists a material universe that develops over the course of
time by means of interactions of tiny material parts with neighboring
tiny material parts.

2\. These interactions are governed by mathematical laws.

3\. These laws entail that the material future is completely determined
by the material past, with no reference to human thoughts, choices, or
efforts.

This conclusion is called: The principle of the causal closure of the
physical. This "Prin­ciple" seemed at one time so secure, and so central
to the scientific enterprise, that some scientists came to view science
as not just an open-minded empirically based inquiry into the structure
of the world, but also as an ideology: i.e., as a tenacious defender of
the dogma that we human beings are essentially material systems governed
exclusively by matter-based laws and hence that our conscious thoughts
can have no actual effects upon our physical actions.

This dogma blocks rational action: One cannot rationally choose to act
to achieve a physical effect if one truly believes that conscious
choices can have no physical effects. One cannot act completely
rationally while truly believing the materialist dogma!

**Quantum mechanics rescinds the materialist dogma.**

Contemporary basic physics -- specifically quantum mechanics -- fails to
validate/vindi­cate/­support The Principle of the Causal Closure of the
Physical!

In spite of this loss of its scientific underpinning, the classical
materialist ideology, in­clud­ing the presumption of causal closure,
continues to infect the thinking of many scien­tists and philosophers.

**The Basic Conflict Between Classical and Quantum Physics.**

Classical mechanics assumed that the ideas that work well for large
objects, such as plan­ets, moons, and falling apples, will continue to
work all the way down to the level of the atoms and molecules.

According to this classical notion, each particle, such as an electron,
has a well defined trajectory in space-time. This idea is illustrated in
Diagram 1. The classical-physics laws of motion ensure that the
trajectories of all the particles (and fields) in the universe at times
earlier than some fixed time t fix the trajectories of all particles for
all future times.

A principal change introduced by quantum theory is the "quantum
uncertainty prin­ciple". This principle asserts that each particle must
be represented, NOT by one single well defined trajectory, but by a
cloud of possible trajectories, as is shown in Diagram 2.

![](media/image1.jpeg){width="4.05in" height="3.5in"}

Diagram 1. [An Evolving]{.underline} [Classical]{.underline}
[State]{.underline}. The diagram shows a possible evolution in time of a
system consisting of three classically conceived electrons. Each
particle has a well defined trajectory in space-time, and each particle
repels the others increasingly as their trajectories come closer
together.

![](media/image2.jpeg){width="4.154861111111111in" height="3.5in"}

Diagram 2. [An]{.underline} [Evolving]{.underline} [Quantum
State]{.underline}. The diagram shows a possible evolution in time of a
system consisting of three quantum mechanically conceived electrons.
Each particle is represented by a cloud of of possible trajectories.

The effect of these uncertainties, if left unchecked, would be
disastrous.

The uncertainties at the atomic level tend to bubble up, irrepressibly,
to macroscopic levels. If the uncertainties originating at the
micro-level were left unchecked from the time of the "big bang", the
macroscopic world would be by now a giant cloud encom­passing all
possible worlds, in stark contrast to the essentially single macroscopic
world that we actually observe.

For example, if the uncertainties were left unchecked then the moon
would be spread out over much of the night sky; And each person's brain
would correspond to a mixture of all of the many alternative possible
streams of consciousness that the person could in principle be having,
instead of corresponding to the essentially single stream of
con­scious­ness that each of us actually experiences.

To deal with this difficulty the founders of quantum theory were forced
to draw a clean conceptual distinction between the two aspects of
scientific practice, the empirical and the theoretical, and to introduce
a special process to account for their interconnection.

The empirical component describes our experiences pertaining to what we
human be­ings do, and to the feedbacks that we then receive. The
theoretical component de­scribes objectively existing "particles and
fields". The process that connects these two aspects of the scientific
description of the world is called the process of measurement or
observa­tion.This feature of the quantum mechanical erects a firewall
that protects the empirical (experiential) realm from the intrusion of
quantum uncertainties from the theoretical realm.

**The Firewall that Holds the Quantum Uncertainties in Check.**

But how are the quantum uncertainties held in check? The theory of the
process of meas­ure­ment was put into rigorous form by John von Neumann,
building on ideas of Werner Heisenberg.

The theory demands that each experience occur in conjunction with an
associated process 1 action. This action specifies a particular
psychologically understandable ques­tion that "nature" must then answer
either 'Yes' or 'No'. (Multiple choice questions can be reduced to
sequences of Yes-or-No questions).

Each such action is a psycho-physical event. *It has two related
aspects*, one in the empirical domain of "our knowledge", and the other
in the domain of the mathematical de­scription.

On the empirical side the action specifies a certain possible "increment
in knowledge": an experientially recognizable 'Yes' response to the
question.

This 'Yes' answer is linked on the mathematical side, to a reduction of
the prior quan­tum mechanical state to that part of itself that is
consistent with the increase in knowledge corresponding to the answer
'Yes'.

If nature fails to deliver the answer 'Yes', then the prior physical
state becomes reduced to the part of itself that is associated with the
answer 'No'.

The process 1 action of *posing* the question is represented in Diagram
3.

![](media/image3.jpeg){width="5.972222222222222in"
height="5.7444444444444445in"}

Diagram 3. [Process]{.underline} [1]{.underline}. Each quantum
(reduction) event has both a psychologically described aspect and a
closely related physically described aspect. Each process 1 event
specifies a psychologically recognizable *possible* experience
associated with an answer 'Yes' to a query. This 'Yes' answer is
associated with a projection operator P that acts on the mathematical
representation of the physical brain. The alternative *possible* answer
'No' is associated with the projection operator P' = (1-P).

Von Neumann calls the physical aspect of this action by the name
"process 1". Two impor­tant facts about process 1 are:

1.  The process 1 actions enter importantly into the dynamics.

2.  Quantum mechanics does not identify any logically sufficient
    physically described cause for this action!

Consequently, the "principle of the causal closure of the physical" is
not entailed by the rules and content of orthodox quantum mechanics!

The measurement process has a second part: the Yes-or-No feedback from
the as­sociated process 1 probing action. This second stage of the
measurement process is called process 3. (Von Neumann gives the name
"process 2" to the continuous deterministic time evolution that is
governed by the Schroedinger equation.) Process 3 picks one or the other
of the two possible answers, 'Yes' or 'No'. This process 3, unlike
process 1, is subject to statistical conditions Process 3 is pictured in
diagram 4.

![](media/image4.jpeg){width="6.241666666666666in"
height="3.566666666666667in"}

Diagram 4. [Process]{.underline} 3. Nature's psychophysical response to
the Process 1 query is either a 'Yes' or a 'No'. The details of the
association between the mental and physical aspects of the events are
installed in the brain in practice by trial and error learning. This
learning made possible by the causal efficacy in the physically
described brain of conscious mental intent.

According to quantum mechanics, the responses/feedbacks conform to
statistical con­di­tions that are specified by the theory.

The choice of the feedback (or outcome) is what Dirac called (see Bohr
1958, p. 51) "a choice on the part of nature".

According to quantum mechanics, this choice of outcome is statistical,
and it lies outside the hands of human beings. The choice of the process
1 probing action is what Heisen­berg called (see Bohr 1958, p. 51) "a
choice on the part of the 'observer' constructing the measuring
instruments and read­ing their recording."

As regards this choice Bohr (1958, p. 73) says: "The freedom of
experimentation \[...\] corresponds to the free choice of experimental
arrangement for which the quantum mathematical formalism offers the
appropriate latitude."

These remarks by the founders of quantum mechanics emphasize the clear
difference be­tween the choices of outcomes, which are statistically
constrained, and are beyond human control, and the choices of our
actions which, in the context of orthodox quantum theory, are considered
to arise from our conscious motives, reasons, and values. We consciously
choose to act in one way or another because of some interest or intent.

The process of measurement creates a firewall that blocks the unfettered
diffusion of the quantum uncertainties into the empirical (or
experiential) realm.

*It is the choice of a process 1 action, **which is not controlled by
any known process, statistical or otherwise**, but which appears to be
influenced by value-based reasons, that, in conjunction with a
stochastic process 3 choice of feedback on the part of nature, con­trols
which potentialities pass through the firewall, and into the realm of
our actual expe­ri­ences!*

**Conclusions**

1.  Quantum mechanics rescinds the materialistic/mechanistic conception
    of human beings.

2.  Quantum mechanics elevates us human beings to active agents; to
    partial-creators of an unfolding universe that is NOT controlled
    exclusively by the material as­pects of reality alone.

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3.  The process 1 action has an important mathematical property: it does
    not change the sum of the diagonal elements of the (density) matrix
    that represents the quan­tum state of the universe. Consequently,
    each process 1 action can be considered to act purely locally in
    some region R, independently of the process 1 actions in regions
    spacelike separated from R. And this process 1 action in R will have
    no effects upon the states of systems in localized regions spacelike
    separated from R. This will ensure that, in accordance with the
    principles of the theory of relativity, no 'signal' can be sent
    faster than light!

4.  On the other hand, there is no logically possible way to accommodate
    all the pre­dictions of quantum mechanics without allowing *nature's
    process of replying* to the questions that we are free to pose to be
    a "global" process, in the sense that the infor­mation about the
    process 1 choice made in some region R must be available in some
    region R' that is spacelike separated from region R.

The effect of this altered conception of ourselves, with respect to our
role in the unfolding experienced reality, is to convert us from the
mechanical automata that classical mechanics has proclaimed us to be, to
local agents that contribute to the evolving reality by posing questions
of interest and importance to ourselves in a way that forces the global
process that creates the facts of nature to respond in ways that allow
us to influence the course of the physically described events. We can
therefore now understand ourselves, within the structure of basic
science, to be not helpless flotsam tossed about by a mindless
mechanical sea, but rather as co-creators, in partnership with a global
creative power, of a universe shaped in part by our own conscious
thoughts.

**A Science-Based Foundation of Ethics?**

Contemporary basic physics leads to a conception of the role in nature
of human beings that is profoundly different from the conception
suggested by the "classical" physics of the seventeenth, eighteenth, and
nineteenth centuries. According to that earlier view, we are helpless,
isolated, mechanisms buffeted about by a mindless mechanical process
that grinds its way pointlessly into a future that was preordained from
the outset. But quantum mechanics allows us to conceive our thoughts to
be, from a science-based viewpoint, causally efficacious,
*value-driven,* locally created inputs to a global creative process that
seamlessly produces the common environment in which we all live. This
understanding stems directly from contemporary science, and is therefore
both science-based and equally available to all human beings, regardless
of ethnic or religious background. This enlargement of our conceptual
horizons provides a science-based undergirding that sup­ports, rather
than undermines, the natural human instinct to work for a common cause
greater than narrow self interest. It also provides a global
species-wide overview for re­solving social conflicts that have arisen
from the narrow parochial origins of our diverse ethical systems.

> This quantum conception of human beings, being based on objective
> science equally available to all, rather than arising from special
> personal circumstances, has the potential to undergird a universal
> system of basic values suitable to all persons, without regard to the
> accidents of their origin. With the diffusion of this quantum
> understanding of human beings, science may fulfill itself by adding to
> the material benefits it has already provided a philosophical insight
> of perhaps even greater ultimate value. (Stapp, 2007, p. 140)

**REFERENCES**

Bohr, N, 1934*. Atomic Theory and the Description of Nature*, Cambridge
UP; Atomic Physics and Human Knowledge, New York, Wiley, 1958.

Stapp, H. P. 2007. *Mindful Universe. Quantum Mechanics and the
Participat­ing Ob­serv­er*. New York: Springer. For more technical details
see also the two new chapters in the third edition of *Mind, Matter, and
Quantum Mechanics*.