Chapter TwoChapter Two

The Philosophical Approach: The Philosophical Approach: Enduring QuestionsEnduring Questions

The philosophy perspectiveThe philosophy perspective

• Philosophy is the search for knowledge.Philosophy is the search for knowledge.• It is the oldest discipline in cognitive It is the oldest discipline in cognitive

science, tracing its origins back to the science, tracing its origins back to the ancient Greeks.ancient Greeks.

• The branch of The branch of metaphysicsmetaphysics examines the examines the nature of reality.nature of reality.

• The branch of The branch of epistemologyepistemology is the study of is the study of knowledge.knowledge.

The mind-body problemThe mind-body problem

• Describes the seeming incompatibility Describes the seeming incompatibility between the physical properties of the brain between the physical properties of the brain and the mental qualities of the mind.and the mental qualities of the mind.

• The brain is material and physical and can The brain is material and physical and can be studied objectively.be studied objectively.

• The mind consists of subjective phenomena The mind consists of subjective phenomena such as thoughts, feelings, and beliefs.such as thoughts, feelings, and beliefs.

• Is the mind physical?Is the mind physical?

MonismMonism

• According to According to monismmonism, the , the mind and the body are both mind and the body are both made up of the same made up of the same substance, either mental or substance, either mental or physical.physical.

• Aristotle (384—322 B.C.) Aristotle (384—322 B.C.) advocated a physical form advocated a physical form of monism. He believed the of monism. He believed the mind and body were both mind and body were both physical.physical.

• He stated that aspects of He stated that aspects of mind correspond to the mind correspond to the different physical states the different physical states the brain assumes.brain assumes.

DualismDualism

• Plato (427—347 B.C.) was a dualist.Plato (427—347 B.C.) was a dualist.• DualismDualism argues that mind and body are of two argues that mind and body are of two

different natures; the brain is a physical substance different natures; the brain is a physical substance and the mind is a mental substance.and the mind is a mental substance.

• Plato thought the body resided in a world that is Plato thought the body resided in a world that is material, extended, and perishable.material, extended, and perishable.

• The mind, he believed, resided in anThe mind, he believed, resided in an ideal world of ideal world of forms that was immaterial, non-extended, and forms that was immaterial, non-extended, and eternal.eternal.

Types of monismTypes of monism

1.1. IdealismIdealism. The mind and body both exist in . The mind and body both exist in a mental realm. There is no physical world.a mental realm. There is no physical world.

2.2. SolipsismSolipsism. A form of idealism in which the . A form of idealism in which the universe exists only in one’s mind.universe exists only in one’s mind.

3.3. PhysicalismPhysicalism. Mind and body are both . Mind and body are both physical. There is no nonphysical world.physical. There is no nonphysical world.

Types of dualismTypes of dualism

1.1. Classical dualismClassical dualism. Proposed by Descartes (1596. Proposed by Descartes (1596—1650). The mind controls the body through the —1650). The mind controls the body through the pineal gland.pineal gland.

2.2. ParallelismParallelism. Mind and body are isolated from . Mind and body are isolated from each other and exist in parallel worlds. An each other and exist in parallel worlds. An unknown force synchronizes the two.unknown force synchronizes the two.

3.3. EpiphenomenalismEpiphenomenalism. The brain causes the mind. . The brain causes the mind. In this view, the mind has no causal influence on In this view, the mind has no causal influence on the brain.the brain.

4.4. InteractionismInteractionism. The mind and the body can . The mind and the body can mutually affect one another.mutually affect one another.

FunctionalismFunctionalism

• A mind is the result of the execution of certain A mind is the result of the execution of certain processes or functions. These functions can give processes or functions. These functions can give rise to mind irregardless of the physical substrate rise to mind irregardless of the physical substrate in which they are embedded.in which they are embedded.

DeterminismDeterminism

• DeterminismDeterminism argues argues that all physical events that all physical events are caused and are caused and determined by prior determined by prior events.events.

• The behavior of a The behavior of a determined physical determined physical system can be system can be replicatedreplicated and and predictedpredicted..

Free willFree will

• According to free will, we autonomously According to free will, we autonomously choose our course of action.choose our course of action.

• Human action is considered independent of Human action is considered independent of preceding causal factors.preceding causal factors.

Evaluating the free will-Evaluating the free will-determinism debatedeterminism debate

• According to According to compatibilismcompatibilism human actions human actions are preceded by causes but these constrain are preceded by causes but these constrain rather than determine our behavior.rather than determine our behavior.

• IncompatibilismIncompatibilism states that we cannot be states that we cannot be truly free of preceding causal events. truly free of preceding causal events. Determinism and free will can therefore not Determinism and free will can therefore not both be true.both be true.

The knowledge acquisition The knowledge acquisition problemproblem

• How does knowledge get How does knowledge get into our heads?into our heads?

• According to According to nativismnativism we we are born with knowledge.are born with knowledge.

• According to According to empiricismempiricism knowledge is acquired knowledge is acquired through experience.through experience.

• The The nature—nurture debate nature—nurture debate argues over the relative argues over the relative contribution of genetics and contribution of genetics and experience to any given experience to any given trait.trait.

Consciousness-The ultimate Consciousness-The ultimate mysterymystery

• ConsciousnessConsciousness may be defined as the subjective may be defined as the subjective quality of experience. What it is like for us to see, quality of experience. What it is like for us to see, feel, think, etc.feel, think, etc.

• The The phenomenal concept of mindphenomenal concept of mind refers to this refers to this subjective aspect of mental life and may never be subjective aspect of mental life and may never be adequately explained.adequately explained.

• The The psychological concept of mindpsychological concept of mind refers to refers to how how the mind causes and explains behavior and is the mind causes and explains behavior and is easier to study.easier to study.

What is it like to be a bat?What is it like to be a bat?

There is something that it is like for a bat to experience echolocation.

Emergent propertiesEmergent properties

• The mind may be an emergent property of the The mind may be an emergent property of the brain.brain.

• Emergence occurs when the global properties of a Emergence occurs when the global properties of a system arise from the more local interaction of its system arise from the more local interaction of its parts.parts.

• Water emerges from the interaction of HWater emerges from the interaction of H22O O molecules but cannot be explained entirely by molecules but cannot be explained entirely by their individual properties or interactions. their individual properties or interactions.

Consciousness and Consciousness and neuroscienceneuroscience

• Consciousness is the emergent property of Consciousness is the emergent property of neuronal activity (Popper & Eccles, 1981).neuronal activity (Popper & Eccles, 1981).

• Consciousness may be the product of specialized Consciousness may be the product of specialized consciousness neurons (Crick & Koch, 1995).consciousness neurons (Crick & Koch, 1995).

• Other theories postulate the existence of a cortico-Other theories postulate the existence of a cortico-thalamic circuit in which information is passed thalamic circuit in which information is passed recurrently between the cortex and thalamus.recurrently between the cortex and thalamus.

Consciousness and artificial Consciousness and artificial intelligenceintelligence

• Can a machine become conscious?Can a machine become conscious?• According to the According to the strong AI viewstrong AI view, the answer , the answer

is yes. It is a matter of building more is yes. It is a matter of building more complex, sophisticated machines.complex, sophisticated machines.

• According to the According to the weak AI viewweak AI view, the answer , the answer is no. Consciousness is either nonphysical is no. Consciousness is either nonphysical or is so complex it can never be reproduced or is so complex it can never be reproduced artificially.artificially.

The Chinese room scenarioThe Chinese room scenario

• Can a person who Can a person who follows rules to follows rules to translate Chinese ever translate Chinese ever understand the understand the language?language?

The multiple drafts theory of The multiple drafts theory of consciousnessconsciousness

• Dennett argues that we are simultaneously Dennett argues that we are simultaneously processing information in multiple streams.processing information in multiple streams.

• Consciousness therefore does not happen at any Consciousness therefore does not happen at any single place in the brain.single place in the brain.