Quantum Mechanics, Minds and Consciousness

Quantum mechanics contains mysteries – Mind and Conscious also contains mysteries – some workers have been tempted to think that they must be connected. As we shall see, this is unlikely.

1. Why the link?

Consciousness and free will seem difficult to reconcile with a fully deterministic physical world. Quantum mechanics (QM) is often brought into the discussion because:

1. QM appears fundamentally indeterministic.
2. Measurement in QM raises questions about the role of observers.
3. Consciousness itself remains poorly understood.
4. Both subjects are surrounded by conceptual puzzles, inviting speculation about a connection.

This connection is often driven by the thought that “two mysteries might solve each other” which seems optimistic at best.

2. Quantum Mechanics and Consciousness

There are several distinct claims here that are often conflated.

It was thought by some that consciousness causes wave function collapse

This idea is associated with interpretations inspired by thinkers such as John von Neumann and Eugene Wigner.

The proposal is that quantum states remain in superposition until a conscious observer becomes aware of the outcome.

Why it seems attractive:

• Measurement is a genuine puzzle in some interpretations of QM.
• Consciousness appears special and difficult to reduce to physics.

Why most physicists reject it:

• There is no empirical evidence that consciousness plays a role in collapse.
• Modern approaches such as decoherence explain much of the appearance of collapse without invoking minds.
• The theory makes few clear, testable predictions beyond standard QM.

A useful point: even if consciousness caused collapse, this would not explain what consciousness is. It would merely assign consciousness a role in a physical process.

Penrose-Hameroff and Quantum Computation in the Brain

This is the famous “Orchestrated Objective Reduction” (Orch-OR) theory associated with Roger Penrose and Stuart Hameroff.

The central claim is that quantum coherence in neuronal microtubules contributes to conscious experience.

Why it seems attractive:

• Classical neural networks may appear insufficient to explain subjective experience.
• Quantum processes are non-classical and potentially richer computationally.

Main criticisms:

• The brain is warm, wet, and noisy, conditions generally hostile to long-lived quantum coherence.
• Evidence for the required quantum states in microtubules remains controversial.
• Even if quantum computation occurred in the brain, it is unclear why this would generate subjective experience.

This last criticism is important. Quantum processing may alter how information is processed, but it does not obviously solve the “hard problem” of why processing should be accompanied by experience. See [Tegmark 2000]

3. Quantum Mechanics and Free Will

This is where many discussions become confused.

The Determinism Problem

Classically, if every event is determined by prior physical states and laws, then it seems difficult to see how genuine alternative possibilities could exist.

Quantum mechanics introduces indeterminacy.

Some people therefore reason:

Determinism is incompatible with free will.

Quantum mechanics is not deterministic.

Therefore quantum mechanics makes room for free will.

Why Indeterminacy Is Not Enough

Randomness is not the same as freedom.

Suppose a decision is produced by a quantum coin flip inside your brain. That would make the outcome less determined, but not more chosen.

A useful formulation is:

• Determinism threatens freedom because actions seem inevitable.
• Pure randomness threatens freedom because actions seem arbitrary.

Free will requires agency, not merely unpredictability.

Thus quantum indeterminacy may remove one obstacle to certain theories of free will, but it does not itself provide a positive account of agency.

This point is emphasized by many philosophers, including Daniel Dennett and Alfred Mele, though they disagree on broader issues.

4. Does Quantum Mechanics Help at All?

A balanced conclusion would acknowledge that QM may help in limited ways.

It may help by:

• Undermining the idea that physics is strictly clockwork-deterministic.
• Showing that the fundamental structure of reality is stranger than classical physics suggested.
• Leaving conceptual room for non-deterministic accounts of decision making.

It does not obviously help by:

• Explaining subjective experience.
• Explaining why experiences have qualitative character.
• Explaining agency or responsibility.
• Turning randomness into genuine free choice.

5. Conclusion

Quantum mechanics changes the metaphysical background against which consciousness and free will are discussed, but it does not by itself solve either problem. Quantum indeterminacy is not the same as agency, and quantum information processing is not the same as consciousness. At present, the quantum theories of consciousness remain speculative, while the philosophical problems they aim to address largely remain where they were under classical physicalism. A good balanced overview of the whole topic can be found in [Chalmers 1996] where David Chalmers discusses and ultimately expresses scepticism about quantum approaches to consciousness, arguing that even if quantum effects are involved, the explanatory gap remains.