philosophy

Philosophy 101, Summer Semester 2021

Handout #3

Paul Churchland, Dualism

Dualism

1. Substance Dualism

· Mind as a distinctive non-physical thing

· Descartes: two kinds of substance make up reality

· Matter (spatially extended)

· Mind/thinking (not spatially extended)

· Mind causally interacts with body

· Reasons:

· Introspection

· Language/mathematical reasoning

· Problems:

· How is causal interaction possible?

· Matter is not usefully conceived as having spatial extension as its core characteristic

2. Popular Dualism

· Mind is literally ‘in’ the body

· Mind/body interaction to be understood as exchange of energy

· Mind might survive death of body

3. Property Dualism

· Mind is a not a substance

· Brain has specific set of properties possessed by no other physical object

· Mental properties not reducible to physical properties

· Different versions

· Epiphenomenalism:

· Mental phenomena emerge when growing brain passes certain level of complexity

· Mental phenomena have no causal power

· Actions exhaustively determined by physical events

· Motivation: conflicting demands of

· Scientifically informed view of brain

· Introspective evidence

· Interactionist property dualism

· Mental properties do have causal power

Arguments in Favour of Dualism

1. Religious belief

· Immortality

· But: not compatible with scientific evidence

· Social forces as determinants of religious belief

2. Argument from introspection

· Apprehension not of neural network, but of thoughts, desires, sensations, etc.

· But: maybe our faculty of introspection not sophisticated enough

· Consider senses

3. Argument from irreducibility

· No physical science capable of accounting for subjective character of experience

· But: consider mathematical skills of computers; computer languages

Arguments against Dualism

1. Ockham’s Razor

· Don’t multiply entities beyond explanatory necessity

2. Explanatory advantage

· Much knowledge about the brain already in place

· Microchemistry, processing of sensory information, neurology

· By contrast: no detailed theory of ‘mind stuff’ available

· Argument from neural dependence: reason, emotion, and consciousness can be shown to be heavily influenced by brain activity

· i.e. drugs, neural damage, caffeine

· Argument from evolution

· Mechanism of evolutionary development

· Occasional blind variation in types of reproducing creatures

· Selective survival of some of these types due to reproductive advantage enjoyed by individuals of those types

· Human species and all of its features are the wholly physical outcome of a purely physical process

· ‘We are creatures of matter’