What Are the
Metaphysical Issues?
 Metaphysics: questions about the nature of reality
 Nature of ultimate reality
 permanence and change
 appearance and reality
 Nature of human reality
 mind-body problem
 freedom and determinism

Metaphysical Positions
 Monism

Materialism

Idealism
 Dualism

Conceptual Tools for
Metaphysics
 Simplification of complexity

Ockham's razor
 Inference to the best explanation
 used by both science and metaphysics

Ontology
 Questions about what is most fundamentally real
 Fundamental reality
 that upon which everything else depends
 that which cannot be created or destroyed

Metaphysical Categories
 Things that are not real: eliminativist strategy
 Realities reducible to more fundamental realities: reductionist strategy
 Things that are fundamentally real

Plato’s Metaphysics
 Nonphysical realities: Platonic
Forms
 Degrees of reality
 Allegory of the cave

Propositions of the Mind-
Body Problem
 The body is a physical thing
 The mind is a nonphysical thing
 The mind and body interact and causally affect one another
 Nonphysical things cannot causally interact with physical things
 These four statements cannot all be true

Positions on the Mind-Body
Problem
 Mind-body dualism

Interactionism

Parallelism

Occasionalism
 Physicalism

Identity theory (reductionism)

Eliminativism
 Functionalism

Descartes’s Arguments for
Mind-Body Dualism
 Principle of the nonidentity of discernibles
 Argument from doubt
• Discourse on the Method
 Argument from divisibility
 Argument from consciousness
• Meditations on First Philosophy

The Cartesian Compromise

Division of reality
• Science’s authority in the physical realm
• Religion’s authority in the spiritual realm

Interactionism

Physicalism: An Alternative to Dualism
 Four problems of dualism:

Where is the mind-body interaction?

How does the interaction occur?

Conservation of energy?

Success of brain science?

The Positive Case for
Physicalism
 Correlation between mental events and brain states
 Consciousness may be a by-product of low-level physical processes

Forms of Physicalism
 Identity theory, or reductionism

Mental events are identical to brain events

Brain research will answer all questions about the mind
 Eliminativism

Labels traditional psychological theories as folk psychology

No beliefs or desires, only brain states and processes

Functionalism
 Minds are constituted by a certain pattern or relation between the parts of a system
 Minds have multiple realizability
 Mental states are defined in terms of their causal role (how they function)

Artificial Intelligence
 Can computers think?
 Turing test
 Strong AI thesis: an appropriately programmed computer can think
 Weak AI thesis: a computer can only simulate mental activities

Issues of Freedom and
Determinism
 How do nature/nurture, heredity/ environment affect us ?
 consider identical twins, separated at birth
 What is the origin of our actions?
 What implication does determinism have for moral responsibility?

Types of Freedom
 Circumstantial
 ability to do what we choose
 freedom from external forces
 Metaphysical
 free will
 relates to our internal condition, not external forces
 Most philosophy is concerned with metaphysical freedom

Positions on Freedom
 Determinism
 Libertarianism
 Incompatibilism
 Hard determinism
 Compatibilism

Hard Determinism
 Problems with libertarianism
 Positive arguments for determinism
 Denial of the possibility of moral responsibility

Objections to Libertarianism
 Conflicts with the scientific world view
 Requires the problematic notion of uncaused events
 Fails to explain that we can influence other people's behavior

The Positive Case for
Determinism
 1. Every event, without exception, is causally determined by prior events
 2. Human thoughts and actions are events
 3. Therefore, human thoughts and actions are, without exception, causally determined by prior events

Determinist Thinkers
 Spinoza
 pantheism
 free will is an illusion
 B.F. Skinner
 radical behaviorism
 reduction of all mental terms to scientific statements about behavioral probabilities

Tenets of Libertarianism
 We are not determined
 We do have freedom of the will
 We have the capacity to be morally responsible for our actions

Objections to Determinism
 Determinism makes an unwarranted generalization from a limited amount of evidence
 Determinism undermines the notion of rationality
 Determinism confuses methodological assumptions of science with metaphysical conclusions

Types of Antideterminism
 Indeterminism

Some events are uncaused
 Agency theory

Event-causation

Agent-causation
 Radical existential freedom

Jean-Paul Sartre

Arguments for
Libertarianism
 Argument from introspection
 Argument from deliberation
 Argument from moral responsibility

Compatibilism
 Soft determinism
 We are both determined and morally responsible for our actions
 Voluntary actions take place when the determining causes reside within the agent, not externally

Hierarchical Compatibilism
(Frankfurt)
 First-order desires
 Second-order desires
 Second-order volitions