Joe Lau

Chalmers on phenomenal concepts and the explanatory gap

Readings

Explanatory gap

  • We might discover that phenomenal state Q is correlated with physical brain state B.
  • But this does not explain why what it is like to be in state B is the same as what it is like to be in state Q. Why can't it be like being in some other phenomenal state R? Or, why can't there be a zombie with state B?
  • What is the gap? Suppose P = conjunction of all physical truths. Q = truth about qualia.
    • Gap = P→Q is not a priori. (knowledge argument, inverted spectrum)
    • Compare: (P→water contains hydrogen) is a priori.
  • Some possible responses:
  1. There is no explanatory gap. We can already close the gap.
  2. There is no explanatory gap, but we are not smart enough to understand why.
  3. There is an explanatory gap now, but more scientific research will fill the gap.
  4. There is an explanatory gap now, but a new kind of science is needed to fill the gap.
  5. There is an explanatory gap, but it is only due to a gap between our phenomenal and physical concepts. There are no ontological consequences.

concept of X vs. X itself

The phenomenal concept strategy

@Proponents of this strategy argue that phenomenal concepts — our concepts of conscious states — have a certain special nature. Proponents suggest that given this special nature, it is predictable that we will find an explanatory gap between physical processes, conceived under physical concepts, and conscious states, conceived under phenomenal concepts. At the same time, they argue that our possession of concepts with this special nature can itself be explained in physical terms.@

Attractive features

  1. Acknowledge intuitive puzzle.
  2. Deflate anti-physicalist conclusions. "conceptual dualism and ontological monism"

Chalmers: Strategy is bound to fail.

@I think that the strategy cannot succeed. On close examination, we can see that no account of phenomenal concepts is both powerful enough to explain our epistemic situation with regard to consciousness, and tame enough to be explained in physical terms.@

@For any candidate thesis C about psychological features of human beings, then either
(I) C is not physically explicable
or
(II) C does not explain our epistemic situation with regard to consciousness.@

Some candidates for C (there are others):

  1. Phenomenal concepts are recognitional concepts.
  2. Phenomenal concepts and physical concepts have different conceptual roles.
  3. Phenomenal concepts are indexical.
  4. Phenomenal concepts are quotational.

The master argument

  1. If P&¬C is conceivable, then C is not physically explicable.
  2. If P&¬C is not conceivable, then C cannot explain our epistemic situation.
  3. Therefore, either C is not physically explicable, or C cannot explain our epistemic situation.

Argument for premise #1

  • If P&¬C is conceivable, then there is an explanatory gap between P and C.
  • If there is an explanatory gap between P and C, then P cannot explain C.

Comments

  • Seems reasonable, especially if the relevant theory of phenomenal concepts are functional / computational.
  • The functional supervenes on the physical.

Argument for premise #2

  • If P&¬C is not conceivable, then zombies satisfy C.
  • Zombies do not share our epistemic situation.
  • If zombies satisfy C but do not share our epistemic situation, then C cannot explain our epistemic situation.

Comments

  • On the phenomenal concept approach, zombies are conceivable but not really metaphysically possible. The approach is supposed to explain why this is the case.
  • So we might try to deny the third assumption. i.e. taking option #4 discussed by Chalmers - "Reject the link between conceivability and explanation"
  • C&¬E is conceivable, but C still explains E. (E is our epistemic situation.)

Category.Mind