The Problem of Free Will
Minds & Machines
Scientific Determinism
• Scientific determinism is the claim that
everything physical is bound by the laws of
physics and that, as such, if some physical
event happens … it could not not have
happened!
Laplace’s Demon
• The mathematician Laplace stated that an
infinitely smart entity could, knowing the
complete state of the universe at time t,
predict exactly what is going to happen.
• Cassandra!
What if Materialism is True?
• What if our thoughts and subsequent
decisions are all the result of neurochemical (i.e. physical) processes … and all
those processes are scientifically
determined?
• … then it seems all our decisions are
determined too.
• Whatever I do … I could not have done
otherwise!
Argument against Materialism
from Free Will
• Determinism is true
• If determinism and materialism are both
true, then we don’t have free will
• We do have free will
• Therefore, materialism is false
The Problem of Free Will
• The Problem of Free Will is that each of the
following 3 statements seem true, but they
can’t all be true at the same time:
– We have free will
– Determinism is true
– If determinism, then no free will
Positions
• There are 3 main positions on the problem of free
will:
– Hard Determinism: Determinism is true, and hence we
don’t have free will. We think we have free will, but
this is just an illusion.
– Libertarianism: We have free will, and hence
determinism must be false.
– Soft Determinism: we have free will, and determinism
is true. This assumes Compatibilism: Having free will is
perfectly compatible with determinism.
Determinism and Fatalism
• Fatalism: I can go to RPI, or I can go to RIT
…. but somehow I will end up with the
same partner!
• Determinism: If I go to RPI … I could not
possibly have gone to RIT!
Indeterminism
• OK, but what about Quantum
Indeterminism?
• First, is quantum indeterminism a fact?
• Second, even if quantum indeterminism is
true, we may still effectively have neural
determinism.
• Third, even if we have neural
indeterminism, how does that give me my
free will back?!
Does Dualism Save Free Will?
• Only if non-physical events can cause
physical events
• But now there are two options:
– The interactions between the physical and the
non-physical are systematic … so we’re back to
determinism: I could not have done otherwise!
– The interactions between the physical and nonphysical are not systematic … so either my
mental decisions are random, or I can’t control
how they translate into my actions.
Compatibilism
• How can free will be compatible with
determinism?
• Maybe some of my actions are determined
(e.g. unconscious ones), while others are
done by my free will.
– But that would go against determinism:
determinism says that *all* of my actions are
determined
Compulsive Behavior
• Maybe an interesting and meaningful
distinction can be made between
‘compulsive behavior’ and ‘free behavior’.
• Both are determined, but only the latter are
‘free’
Free Will is Making Choices?
• Maybe to have free will is to be able to
make choices
• The outcome of the choice is determined,
but there is still a ‘choice-making’ process
we can point to
• E.g. Chess Computer
Quiz 1
• Everything is determined, so we have no free will
• This position is called:
•
•
•
•
A. Hard Determinism
B. Soft Determinism
C. Fatalism
D. Libertarianism
Quiz 2
• Which of the following diagrams, showing
the possible ways the world can proceed
through time, captures Determinism?
t0
tn
A
B
C