Test 3

Minds and Bodies Review The Questions

• What am I? – What sort of thing am I? • Am I a mind that “occupies” a body? • Are mind and matter different (sorts of) things? • Is conscious awareness a physical event or something that happens in an immaterial soul? The “Landscape” How many kinds of “stuff?”

Dualism: Monism: Minds and Matter Idealism: Materialism: Everything Everything is Descartes is mental material Berkeley

Identity Eliminative Epiphenominalism Materialism Theory

Mental Qualia are There states are causally are no identical to impotent. mental brain states, states, just just like like water Jackson there are Graziano is identical no to H2O. ghosts. Descartes

• I can conceive of myself without a body, – As a disembodied mind. • I cannot conceive of myself without a mind, – As a mindless zombie. • So, having/being a mind is an essential property, while • Having a body is merely an accidental property. Life After Death?

• If there is such a thing as life after death, then there must be a “part” of you that continues to exist after the death of your body. • So, if you believe in life after death, you are already committed to the idea that you are something distinct from your body … – i.e., distinct from any material object. Descartes

• A Dualist – Descartes thinks that what I am is a mind, and that I occupy a material body. • “Thinking” (being conscious) is an essential property. • “Being extended” (occupying space—having a body) is merely an accidental property. – So, there are two fundamental and distinct basic kinds of stuff: mind and matter. Mind/Body (or Substance) Dualism: There are two distinct, fundamental and irreducible, sorts of things in the world…

MINDS BODIES (Matter)

• Conscious Beings: • Material Beings: – Non-material beings which – Material (“corporeal”) beings are the subjects of conscious that cannot be the subjects of experience. conscious experience. • Descartes: • Descartes: – Res cogitans – Res extensa – “Thinking” but non-extended – Extended beings (beings that beings (beings that do not occupy space), but are not occupy space). capable of “thinking.” Descartes’ Arguments for Dualism

• Bodies are divisible. Minds are not. So they cannot be one and the same thing.

• “Mind” and “Matter” are conceptually distinct—the concept of each is independent of the concept of the other. So it is conceptually possible for one to exist without the other. So they must be metaphysically distinct. A Problem: Causal Interaction

• On Descartes’ view (dualism), minds and bodies are fundamentally distinct kinds of things, distinct kinds of “substance.” • And yet, he believes they causally interact with one another. – Exp.: Sense perception, willful action. • But it seems impossible to explain how things with nothing in common could “influence” each other. What are “Mental States?”

• A “mental state” is just a state or condition some person might be in, like seeing, thinking, being in pain, willing, desiring, etc. – So, thoughts, pains, desires, beliefs, etc., are all “mental states.”

• We will use this term in a “neutral” way, that is, without presupposing either dualism or materialism. – We need to have some way of talking about these things that doesn’t “takes sides” in the dispute. The Options

• According to the dualist, mental states are states of an immaterial mind or soul. • There are different varieties of materialism: – According to the Identity Theory (which Carruthers supports) mental states are identical to brain states. – According to Eliminative Materialism (a version of which was held my Graziano), there are no such things as mental states. Two Varieties of Materialism:

The Identity Theory: Eliminative Materialism: • Mental states (thoughts, • There really are no such things sensations, etc.), are as “mental states” (“thoughts,” identical to states of the “sensations,” etc.): brain and/or central nervous system: – Like ghosts or “caloric,” we used to believe in them. We haven’t learned what they “really” are – In the way in which water is (what they are “identical to”): identical to H2O, or lightning is identical to rather, we have learned that they discharges of electricity in really aren’t, i.e., that there are no the atmosphere. such things. Carruthers: Identity Theory

• Carruthers turns a problem for dualism into an argument against it (an argument for “the identity” theory). – 1) Only physical events can cause physical events; – 2) Yet thoughts (mental states) can cause physical events (willful action); – 3) So thoughts (and other mental states) must be (must be “identical to”) physical events. The Identity Theory • Rejects Dualism: a variety of Materialism. • Claims that everything that exists is, ultimately, material. • Unlike Eliminative Materialism, accepts that mental states are, in some sense, “real.” • But claims that what they really are are states of the brain and/or central nervous system. – So thoughts (and other “mental states”) are identical to brain states in just the way that water is identical

to H2O. Carruthers and Leibniz’ Law

• Carruthers argues that mental states are identical to brain states: dualists disagree. • So, the debate concerns whether or not these things are identical. • Leibniz’ Law states a general truth about identical things: if two things are identical, they have the same properties. – So if things have different properties, they cannot be identical. Carruthers’ Rebuttals

• Objection: The Argument from Certainty – I can be certain of mental states, but not brain states. – C: “being such that I can be certain about it” is not a property that things have. • Objection: The Argument from Color – I can have green after-images, but brain states can’t be green. – C: After-images aren’t actually green. The “Landscape” How many kinds of “stuff?”

Dualism: Monism: Minds and Matter Idealism: Materialism: Everything Everything is Descartes is mental material Berkeley

Identity Eliminative Epiphenominalism Materialism Theory

Mental Qualia are There states are causally are no identical to impotent. mental brain states, states, just just like like water Jackson there are Graziano is identical no to H2O. ghosts. Jackson

• A “Qualia Freak” – Qualia: What it’s like to smell a rose, etc. • There are “truths” about what it is like to smell a rose, etc. • These are not “truths” of physics. • So, there are truths that are not truths of physics. Jackson’s Dilemma

• Jackson recognizes there are truths about what it is like to smell a rose; • And believes that these truths are not truths of physics. • Dilemma: Doesn’t claiming there are truths that are not truths of physics force one into dualism? Doesn’t this force one to reject materialism? Jackson’s Solution • Distinguish (mere) “Materialism” from (what he calls) “Physicalism.” – Materialism: Everything that exists is material. – Physicalism: Materialism plus the claim that all truths are truths of physics. • Jackson is forced to reject physicalism. • But accepting materialism while rejecting physicalism leaves him with Epiphenomenalism. Epiphenomenalism • What you get if you accept qualia (truths about what experience is like) while rejecting dualism. • Qualia are real, but causally impotent: they are caused by physical events, but cannot themselves cause physical events. • So, the world wouldn’t be any different if we were all “zombies.” – Consciousness is “real” but doesn’t do anything. Why can’t qualia cause?

• According to science, all causes are physical, and so must be describable in the terms of physics. • But qualia, Jackson has argued, cannot be described in the terms of physics – (Facts about them are not facts of physics.) • So, qualia cannot be the causes of physical events. • Epiphenomenalism is the view that qualia real, but causally impotent. Mental States and Causality The Turing Test

• How could we tell whether or not a computer could “think?” How could we tell if it was “conscious?” • Turing proposes a “test,” and says if a computer could pass it, we would have to say that it thinks. – The test involves answering question in a way that could “fool” us into believing we were talking to a human being. The Issue

• Turing’s discussion of the “Objection from Consciousness” helps us understand the core of the issue. • We cannot see “inside” other people’s minds, and yet we believe they are conscious. – So, we must believe this because of how they “behave”— specifically, how they “talk.” – If a computer behaves in the same way, we must either admit that it thinks or deny that other people think, because we use the same “test” in both cases.