Review

Dualism vs. Materialism

Dualism: •  There are two fundamental,

distinct kinds of “substance,” –  Matter: the “stuff” the

material world is composed of; and

–  Mind: the “stuff” that that has mental awareness, the kind of thing that can be the subject of conscious experience.

Materialism: •  There is one fundamental

kind of substance: –  Matter: the “stuff” the

material world is composed of.

–  There is no other basic kind of stuff. Everything that exists is, in the final analysis, composed of matter (i.e., atoms, etc.)

Metaphysical, yet Personal

•  Dualism and Materialism are different metaphysical positions. – They make different claims about the fundamental

nature of reality. •  But the debate arises from a highly personal

question: – What is it to be me? – What kind of thing am I, as a conscious being?

“The Qualia Problem” Frank Jackson

The Question

“I am what is sometimes known as a ‘qualia freak’.”

(OK, you’re a freak! But…)

What in the world are qualia?

Quale

•  The “felt quality” of a conscious experience. – “Quale” is singular, “Qualia” is plural.

•  There is something that “it’s like” to be conscious, to have a sensation, to see an after-image.

•  “Qualia” is a word introduced to help us talk about what “it’s like” to be conscious.

What are qualia?

•  “… the hurtfulness of pains, the itchiness of itches, pangs of jealousy, … the characteristic experience of tasting a lemon, smelling a rose, hearing a loud noise, or seeing the sky.”

•  The “raw-feels” of conscious experience: – What it’s (consciously) like to feel pain, see a

color, smell a rose, hear a sound, etc.

Quale, Anyone?

•  Conscious experience “from the inside.” •  Each person has their own awareness of

what their own consciousness “feels like” (what a rose like to them, what green looks like to them, etc.), but no direct experience regarding anyone else.

•  Qualia are necessarily subjective, and so, what they are like cannot be captured by any objective description.

The Position

Jackson’s claim:

•  1) The existence of qualia is incompatible with the truth of physicalism.

•  2) But qualia exist. •  3) So, physicalism must be false.

•  Terminology: – Jackson uses “physicalism” to describe a specific

version of materialism.

What is physicalism? •  “The theory that all information [truth] is ultimately

physical information [truth]—information [truth] about physical states and physical events, couched exclusively in physical terms.”

•  I.e., the view that … –  1) everything that exists is physical (material)

•  (this is simply what materialism says) , and that –  2) everything can, in principle, be fully described and

explained by physical (material) theories. •  I.e., a “completed” physics could explain everything.

Physicalism vs. Materialism

•  As Jackson uses these terms:

– Materialism—The metaphysical claim that the only fundamental substance is matter. •  Materialism involves a rejection of dualism.

–  Physicalism—The above plus the claim that everything can (in principle) be explained by the laws of physics. •  So, for Jackson, physicalism is a specific version of

materialism.

Jackson’s View

•  The way Jackson uses these terms, “physicalism” says something more than “materialism.” – “Physicalism” = “Materialism” + “every fact is

a physical fact; every truth is a truth of physics.”

•  This is important because Jackson will accept materialism but reject physicalism.

The Argument

Jackson’s Argument:

•  1) The existence of qualia is incompatible with the truth of physicalism.

•  2) But qualia exist. •  3) So, physicalism must be false.

•  Jackson thinks … –  2) is known by experience to be true. (We all know that

there is something that it is like to be conscious.); –  but 1) must be argued for (which he is about to do), in

which case, 3) will follow.

The knowledge argument for qualia:

•  1) Suppose that one knew everything there is to know about the make-up of the physical world and the physical theories explaining it.

•  2) One would still not (in virtue of this knowledge)

know what it was like to feel pain, smell a rose, etc. •  3) “Therefore, knowing all this is not knowing

everything …. There is something that physicalism leaves out.”

The Argument: An Illustration

Fred’s color experience:

•  Suppose that Fred sees two shades of red that no one else can differentiate (i.e., both shades “look the same” to everyone else). –  He can consistently discriminate the two different colors. –  He tells us that they “look” (to him) very different.

•  Suppose we know everything there is to know about Fred’s brain and eyes.

•  Even so, this would not allow us to know what “the other red” looks like.

Fred’s color experience (cont.) •  Suppose that we all have operations to make our

brain and eyes work just like Fred’s. •  After the operation, we will see the two shades of

red, and know what the “other shade” looks like. •  So, we will then know something new, something

that we didn’t know before the operation, even though we knew everything there was to know about the operation of Fred’s brain.

The Conclusion

Jackson’s conclusion: •  “ … one can have all the physical information without

[thereby] having all the information there is to have” (without, that is, knowing what it feels like to have a given experience).

•  Physicalism says that everything can be explained in terms of physical explanations.

•  But, we have just shown that we can know all the physical

explanations there are to know without knowing everything, i.e., without knowing what qualia are like.

•  So, the existence of qualia proves that physicalism must be

false.

Qualia vs. Physicalism:

•  Physicalism: – 1) everything that exists is physical (material);

and – 2) everything can, in principle, be fully

described and explained by physical (material) theories.

•  The existence of qualia, Jackson argues, conflicts with 2), but not necessarily with 1). – That is, rejecting 2) doesn’t necessarily imply

substance dualism.

Analysis

Jackson: Dualism is not the only alternative to Physicalism

•  Jackson thinks that physicalism is false – but does not therefore infer that substance

dualism must be true. • That is, he rejects physicalism but does not

reject materialism. •  So, what is the alternative? – How can he accept materialism and deny

physicalism?

“The Bogey of Epiphenomenalism”

•  Epiphenomenalism: “ … the idea that qualia are causally impotent with respect to the physical world.” –  i.e., the view that even though qualia exist and are caused

by events in the physical world •  (e.g., the way the world interacts with our sense organs and central

nervous system),

–  qualia do not themselves cause changes in the physical world •  (i.e., they are “causally impotent” with respect to it).

Definitions:

•  Epiphenomenon: – a phenomenon that occurs with and seems to result

from another but has no reciprocal effect or subsequent influence; •  A causally inert byproduct.

– Applied to consciousness regarded as a by-product of the material activities of the brain and nerve-system. [Oxford English Dictionary]

Definitions: •  Epiphenomenalism: – Epiphenomenalism is the view that mental events are

caused by physical events in the brain, but have no effects upon any physical events. Behavior is caused by muscles that contract upon receiving neural impulses, and neural impulses are generated by input from other neurons or from sense organs. On the epiphenomenalist view, mental events play no causal role in this process. [Stanford Encyclopedia of Phil.]

Epiphenomenalism

•  There is something “it’s like” to be conscious, to feel pleasure or pain; something that it feels like to be happy or sad, etc.

•  But none of this has any causal impact on the world.

•  That is, nothing would be any different if we were all “zombies,” if we had no “inner life.”

•  So, yes, we have an “inner life,” but this has no effect on anything.

Dualism vs. Epiphenomenalism

Phsical

Stimuli

Behaviorial

Resonses

Mental State

Mental States and Causality

So, Epiphenomenalism says that what red looks like (to us) …

•  … is caused by events in the physical world; –  i.e., its real (we really have such experiences), but

•  … does not itself cause changes in the physical world; –  i.e., it is not a necessary part of any theory or

explanation of what goes on the physical world, including human behavior.

An Objection Rebutted

Qualia are an excrescence*: “They do nothing, they explain nothing…”

•  “This is perfectly true, but no objection to qualia….” – “ … it rests on an overly optimistic view” of

what human beings can know. •  I.e., just because we can’t explain them, this

doesn’t mean that they don’t exist.

•  *excrescence: 1. The action of growing out or forth. Also, immoderate growth, overflow, abnormal increase. [Oxford English Dictionary]

Summary

Qualia and Physicalism:

•  Physicalism: –  1) everything that exists is physical (material), –  2) everything can, in principle, be fully described and explained by

physical (material) theories.

•  For Jackson, the existence of qualia is … –  incompatible with 2), but –  not necessarily incompatible with 1).

•  We don’t really know what qualia “are.” •  So, epiphenomenalism (i.e., qualia exist, but are causally impotent)

doesn’t necessarily entail substance dualism, i.e., there is something that physicalism can’t explain, but that doesn’t necessarily mean there is a non-physical substance— –  Maybe, there are non-physical properties (a.k.a property dualism).