Transcript Lecture 10: Materialism II

LECTURE 10: MATERIALISM II
The mind-body problem
In Today’s Lecture we will:
1. Briefly recap our investigation into the mind-body problem
2. Outline and become introduced to the problem of freedom
3. Examine and discuss the theory of Determinism
4. Outline and critically examine three contemporary approaches to the
question of reality
5. Conclude our investigation into the question of reality
TODAY’S LECTURE
RECAP
So far in phi 100...
o We are continuing our investigation into the metaphysical question, what is
reality?
o We have considered a number of possible answers:
o Thales: Reality is composed of water
o Plato: Reality is composed of two worlds; Being and Becoming
o Descartes & Locke: Reality is composed of physical and mental
substances
o Berkeley: Reality is composed of ideas or mind
o We investigated an important consequence of Descartes’ dualism:
The mind-body problem
o And a number of attempts to resolve the problem:
o Descartes: Tried to find the location in which mind and body interact
o Ryle: Denies the problem itself is valid
o Berkeley: Reduced reality to one substance; mind
o Materialist Monism: Reduces reality to one thing; matter
RECAP
In our previous lecture we examined the following theories:
o Materialistic monism
The theory that everything is composed of one thing; matter, physical
substance etc.
o Behaviorism
Hard Behaviorism: Denies the existence of the mind, mental events,
thoughts etc.
Soft Behaviorism: Does not deny that the mind may exist but we should
limit our investigations to observable, quantifiable behavior.
o The Mind-Brain identity theory
The theory that mental states are identical with brain states
o Functionalism
A theory which attributes minds and mental states to any system that
performs functions
RECAP
THE PROBLEM OF FREEDOM
Mechanistic Materialism
Maintained that humans are composed entirely of physical matter
All matter is governed by physical, causal laws of nature
All human actions are, therefore, governed by causal laws of nature
The consequence is that the universe, including everything in it is one big
machine
FREEDOM
Newton’s Laws
1. A body remains at rest or in motion with a constant velocity unless
acted on by an outside force
2. The sum of the forces acting on a body is equal to the product of its
mass and acceleration
3. For every action there is an equal opposite reaction
Everything that happens is the result of a prior cause
And could not happen other than it did
Force
FREEDOM
The problem of freedom
Our problem is this:
If humans are entirely composed of matter
And all matter is governed by laws of nature
Then it follows that human actions are governed by laws of nature
Therefore there can be no such thing as freedom or choice
FREEDOM
Key Questions
What do we mean by freedom?
Does freedom exist, or is there only necessity?
How is freedom possible in a world governed by natural laws?
Can we ever know whether there is freedom?
If there is freedom, is it an either-or proposition, or are there degrees of it?
Do any of these questions matter practically, or are they only of academic
interest?
What are the consequences if there is no freedom?
FREEDOM
HARD-DETERMINISM
Determinism Claims:
A. Every Event Has A Prior Cause
B. Human Actions Are Events
C. Causation and Freedom are incompatible
D. Determinism Must Be True
o Argues that Causation and Necessity are incompatible with
freedom
o Denies that humans have any choice and that there is no such thing
as human freedom
o Instead; human acts, as events, are all a result of prior necessary
causes and therefore not free.
HARD-DETERMINISM
What is freedom?
A free action is an action which is free from necessity and causation
A free action could have happened other than it did
Every time a decision is made there may be a different outcome
Choice A
Choice B
Agent
There is no necessity or causation
influencing the agent’s decision
HARD-DETERMINISM
Causation
Most Scientific Theories depend on Causal Explanations
The relationship between a cause and its effect is often expressed as a law
For Example: F=MA; E=MC2 ; XY
Scientists maintain that all events are the result of prior causes (A)
C1
C2
C3
HARD-DETERMINISM
C4
C5
Event (E)
Necessity
Most scientific theories also assert that if we have a cause (C1) and an
event (E1) then E1 will always result from C1 (C1E1)
E is a necessary cause of C1.
An event (E) could not be other than it was.
C1
C2
C3
C4
C5
Event (E)
C1
C2
C3
C4
C5
Event (E)
HARD-DETERMINISM
1
Stepping on
Nail
2
Nerves Send
Pain Signal to
Brain
3
4
Neurological
Processes
5
Pain
Behaviour
A. All physical events are bound by necessary causal laws
B. Brain processes are physical events
C. Human brains are bound by necessary causal laws
HARD DETERMINISM
Hard-determinism
1.(a)There Is No Such Thing As
Freedom Or Choice (They Are All
Illusions)
2. (a) Every Event (Including
Human Actions) Has A Prior,
Necessary Cause.
3. (a) Freedom And Necessity Are
Incompatible
HARD-DETERMINISM
Experience
1.(b) But We Think/Feel That We
Do Have Freedom And
Choices
2.(b) All of our science and
understanding of the world is
based on necessity and
causality (2a is true).
3.(b): 1b and 2b Can’t both
be true (Either/Or).
If determinism is true:
Although we may think we have freedom, choices or responsibility; we
don’t. They are all illusions!
We cannot be held responsible for our actions (whether for reward or
punishment)
Everything that we have done/are doing/will do was pre-determined before
we were even born.
HARD-DETERMINISM
CONTEMPORARY APPROACHES
1. Quantum Physics
Challenges the determinist’s causal model
Suggests that the world is not determined so strictly as determinism maintains
Distinguishes between the quantum (micro) and macro world
In the quantum world:
o
The standard laws of nature do not apply
o
There may be events without causes
o
Not all events are necessary
o
Some scientists even claim that there is no such thing as necessity (or
impossibility)
o
Events can only be predicted using statistical probabilities
QUANTUM PHYSICS
Macro Level
Quantum Level
QUANTUM PHYSICS
Problems with quantum physics
There is an ongoing investigation into how the quantum world and our world
are related
How do we go from tiny atoms to objects?
Where does the quantum world begin and end?
Is the brain determined by quantum or Newtonian laws?
It is not clear whether our world is governed by the same laws that apply to the
quantum world
Billiard balls do not suddenly move without being caused to move
Objects do not suddenly vanish or appear into and out of existence
We can predict the motions of objects with relative accuracy
Objects in our world are stable and solid
QUANTUM PHYSICS
2. Property Dualism
Endorsed by thinkers such as David Chalmers
Distinguishes between physical and mental Properties
Chalmers maintains:
Mental Properties (mental events, minds, thoughts etc.) are real features
of the world
Any successful theory of reality must include consciousness as a
fundamental feature of reality
There must be basic laws that relate conscious life to the rest of reality
Once these laws are understood the relationship between mind and brain
will no longer be a mystery
PROPERTY DUALISM
Implications of Property Dualism
If property dualism is correct:
Scientists and philosophers need to seek and uncover new laws of nature
that explain how conscious life and reality are interrelated
Such laws may show that human actions are not strictly determined
Criticisms of Property dualism:
It is unclear whether these “psychophysical bridging laws” may exist
It is also unclear how we might go about finding or investigating such
laws
Little evidence in support of the existence of such laws
PROPERTY DUALISM
3. Emergence
The ‘Principle of Emergence’ maintains that minds are an ‘emergent’ feature
of brains
Posits the existence of two distinct ‘levels’ in the brain
The ‘Supervening’ level emerges as a result of the ‘lower’ level’s physical
processes
A change at one level effects the other
For Example:
H20 Cannot be ‘Wet’ or ‘Frozen’ but water (the system) can
Humans can be conscious but neurones and synapses cannot be
EMERGENCE
Frozen
Water
Supervening Level
Lower Level Processes
EMERGENCE
Liquid
Water
Evaporating
Water
I am hungry
I am thinking about eating turnips
Supervening Level
Lower Level Processes
EMERGENCE
I want to eat that
candy bar
I wonder if Apolo Ohno
will win Gold
Implications of theories of emergence
If the theory of emergence is correct:
Theories of emergence may show that the brain is not as strictly
determined as determinists maintain
Brains are unique; they are the only things with minds
Criticisms of the theory of emergence:
It is unclear how the brain generates consciousness
We lack a scientific understanding of how such processes may work
It is also unclear how we might go about finding or investigating such
processes
EMERGENCE
THE END OF METAPHYSICS
Ongoing Perplexities:
The scientist maintains that everything has/is/will be explainable using
scientific inquiries
However there are a number of things the scientist is unable to explain:
Human Freedom
Human Consciousness
The relationship between mind and body
The nature and laws that govern the universe and everything in it
CONCLUSION
Where do we go from here?
Philosophical inquiries can help to show the limits and mistakes inherent in
the scientific world-view
Some of the things that scientists cannot yet explain may be explained at a
later date
The inquiry into the question of reality may show that there are some things
that scientists are unable to explain
There may be some things that can never be explained or understood. Some
things may always remain as fundamental mysteries to us
To be continued...
CONCLUSION