In 1637, Descartes argued that the physicalism of science and the idealism of religion are both true, as matter was a substance in space and a mind was a substance outside it, but two centuries later, Laplace rejected this, arguing that matter alone determined the universe:
“We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.” Laplace, in (Truscott & Emory, 1951) p4.
He challenged the dualism of mind and matter by claiming that the laws of physics explained everything, so science not only didn’t need religion but was better off without it. The case against dualism was that all physical events have a physical cause, so the universe is causally complete. It is a causal chain with no gaps, so if one pushes one end of a tube of balls, a ball pops out the other end and no mind or soul is needed to make it happen. That all physical facts come from other physical facts leaves no room for non-physical causes. Causal closure implies that if mind has a physical cause, it is also physical and so not mind, and if not, it can’t have a physical effect at all (Kim, 1999). Causal closure implies that a non-physical mind can’t affect physical events.
Supporters of dualism tried to demonstrate non-physical causes by paranormal events but attempts to replicate mental powers, like the ability to move objects (telekinesis) or to see the unseeable (extra-sensory perception), hasn’t been definitive (Kelly at al., 2007).
But just as physical realism was demolishing dualism with its mechanical universe vision, it took a crippling blow from the new kid on the block, quantum theory. It states that no physical event is 100% certain and the evidence agrees, as in the Stern-Gerlach experiment, silver atoms in a magnetic field go up or down based on a spin that is perfectly random. We can’t sort the atoms into those going up or down in advance because they are initially identical and the spin direction that moves them in a magnetic field is decided when they interact with it, not before. Quantum theory says it happens when an atom observes the field, just as where a photon hits a screen happens when it observes the screen. In a mechanical universe, the physical history of a physical event should completely define it but in our universe that isn’t so. In quantum theory, every quantum entity chooses by itself how it physically interacts and this unpredictability is inherent to reality itself.
According to quantum theory, when a quantum wave is observed, it randomly actualizes a physical event from one of its lawful possibilities and obliterates the rest. This stops the quantum wave expanding endlessly by restarting it. An observer outside the quantum system ends the chain of quantum events but the universe as a closed physical system has by definition nothing outside itself to do this.
In contrast, physical realism doesn’t allow an observer. An endless physical chain with no gaps has no way to select one link to be an observation, so physical realism denies both the observation and randomness we know occurs. It’s a nice simple theory but it doesn’t recognize the fact that we observe and there is randomness. Quantum realism accepts both by accepting quantum theory but not physical realism.
Figure 6.2 compares the reality options:
a. In physical realism, a series of physical events (P) lawfully cause each other with no gaps, so there is no observation or randomness.
b. In dualism, a series of physical events together with non-physical mind events (M) affect physical events, so miracles can deny physical laws.
c. In quantum realism, a series of quantum observations (O) cause randomly-seeded physical events, so there is both randomness and observation, as all physical laws derive from quantum laws.
In Figure 6.2a, reality is one set of physical events causing the next, with no randomness or observer possible, so there can be no evolution and no observing “I”.
Figure 6.2b is more complex, as two different event sets, mental and physical, affect not only their realm but also the other, but that mind events can supersede physical events is unproven.
In Figure 6.2c, reality is a series of observations each leading the next as in quantum theory. Each physical event is the observed result of quantum events but has itself no further effect, so physical events cause nothing. Physical reality is an epiphenomenon that, like a train whistle, appears but doesn’t affect the quantum engine that drives reality.
Physical events link lawfully to each other by their quantum precedents so physical laws are correlations not causality. Quantum reality creates physical reality and quantum laws create the physical laws we deduce. The quantum sequence leaves no gaps for physical causes to explain just as physical causality left no gaps for mental causes to explain. When the quantum world chooses a physical event from those possible, it selects a thread from the future timeline options.
Physical realism has no observer or choice but quantum realism has both because every quantum collapse is an observation choice. The observer is why quantum theory works when physical realism doesn’t..