Questions: Supervenience of Mental Properties on Physical Properties

Question 1

Two systems are physically identical in every detail — same atoms, same configuration, same causal history. According to strong mental-on-physical supervenience, what must be true?

• A. They have the same mental states, because mental properties just are physical properties described at a higher level of abstraction.
• B. They must have the same mental states, because no mental difference is possible without a physical difference — supervenience rules out physically identical systems with different mental states.
• C. They may have different mental states, because supervenience is only a statistical tendency across possible worlds.
• D. They have the same mental states only if they are conscious beings, not for systems that merely process information.

Answer: (B)

Strong supervenience states that necessarily, any physically identical world is also mentally identical. If two systems are physically indistinguishable, they cannot differ mentally — no mental property can vary independently of physical properties. Option A describes the identity theory (mental = physical), which is stronger than supervenience: supervenience allows mental properties to be real and irreducible while still depending entirely on the physical. Option C misunderstands supervenience as merely probabilistic.

Question 2

A philosopher accepts that mental properties supervene on physical properties. Does this commit her to the view that mental properties are reducible to physical properties?

• A. Yes — supervenience just is reduction under a more technical description.
• B. No — supervenience states dependence without reduction; non-reductive physicalism holds that mental properties supervene on physical ones while remaining genuinely distinct and irreducible.
• C. Yes — once you accept supervenience, functionalism and type-identity theory both follow as immediate consequences.
• D. No — supervenience is actually incompatible with physicalism of any kind.

Answer: (B)

This is the key conceptual distinction in the topic. Supervenience is a dependence claim: mental properties cannot vary without physical variation. Reduction is a stronger claim: mental properties just are physical properties (or can be fully defined in physical terms). Non-reductive physicalism occupies the middle ground — it accepts supervenience (mental depends on physical) while denying reduction (mental cannot be eliminated in favor of physical descriptions without loss). Beauty supervening on pigment without being reducible to it is the standard analogy.

Question 3

If strong supervenience holds, a physical zombie — a being molecule-for-molecule identical to a conscious human but lacking any subjective experience — is metaphysically impossible.

• T. True
• F. False

Answer: True

Strong supervenience says that any world physically identical to ours is also mentally identical. A zombie world, by definition, is physically identical to ours but mentally different (no consciousness). If strong supervenience holds, this is impossible: the physical facts fix the mental facts across all possible worlds. Whether strong supervenience does hold — and therefore whether zombies are genuinely conceivable — is a major debate in philosophy of mind, but the logical entailment is clear.

Question 4

Accepting that mental properties supervene on physical properties resolves the problem of mental causation by establishing that mental properties have genuine causal power alongside physical properties.

• T. True
• F. False

Answer: False

Supervenience generates the problem of mental causation rather than resolving it. If mental properties depend on physical properties without being identical to them, and if physical causation is closed (every physical effect has a sufficient physical cause), then mental properties appear causally redundant — they supervene on whatever does the causal work without contributing anything additional. This is the exclusion problem: the physical explanation seems to exclude any separate mental causal contribution. Supervenience tells us mental properties are not independent; it leaves entirely open whether they do any genuine causal work.

Question 5

Explain the difference between supervenience and reduction, and describe how non-reductive physicalism uses supervenience to occupy a middle ground between full reduction and dualism.

Model answer: Supervenience is a dependence claim: no mental difference without a physical difference. Reduction is a stronger identity or definability claim: mental properties just are physical properties, or can be fully defined in physical terms without remainder. Non-reductive physicalism accepts supervenience (mental depends entirely on physical — no free-floating mental properties) while denying reduction (mental descriptions capture something real that purely physical descriptions cannot replace). This avoids dualism (which allows mental properties to vary independently of physical ones) without collapsing into eliminative or reductive physicalism (which denies that mental properties are genuinely distinct).

The painting analogy makes this vivid: a painting's beauty supervenes on its physical substrate (an exact physical duplicate would be equally beautiful), but 'beautiful' cannot be replaced by a chemical formula without losing something important. Similarly, pain supervenes on C-fiber firing (or whatever the physical base is) without being identical to it. The philosophical burden non-reductive physicalists then face is explaining why, if mental properties are not identical to physical ones, they are not causally irrelevant — the exclusion problem that builds directly on this topic.