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