Hi I’m Mason Westfall.
I teach philosophy at the University of Toronto,
and today I want to talk to you about the problem of other minds.
Have you ever wondered whether other people have feelings like yours?
Maybe what you see as red, others see as green.
Perhaps others don’t experience the world at all.
Maybe what looks like other people
are really just robots that don’t have minds at all.
Philosophers call this ‘the problem of other minds’.
How do we know that others have experiences like we do, if we know at all?
People who think we can never really know that others have
minds like ours are called ‘skeptics’ about other minds.
Why might someone be a skeptic about other minds?
Skeptics point out that we seem to know about our own
experiences directly--we have immediate access to our
own feelings and perceptions-- while we can only learn
about others’ experiences from their outward behaviour.
So the skeptic makes an assumption about what we
have immediate access to: namely, our own minds,
and the things that we can perceive in the external world,
like physical facts and body movements.
How can we know about the minds of others?
Skeptics about other minds say that this is impossible.
To make their argument, skeptics often appeal to a skeptical scenario.
A skeptical scenario is a possible situation in which things would seem
just as they actually seem, and yet many of your beliefs would be false.
Let’s consider what philosophers call an ‘inverted spectrum’ case.
Suppose you and I are looking at a ripe strawberry.
Although we’re looking at the same strawberry,
maybe it looks different to each of us.
Maybe, the color of the strawberry appears to me as the color a lime appears to you.
Because of how we learn color words, though,
we both call the same objects red and green.
I say that limes are ‘green’, and ripe strawberries are ‘red’, just like you do.
But what I experience when I look at a lime is the
color that you experience when you look at a strawberry.
So our experiences are inverted with respect to one another.
How can you be confident
that my color experience is not inverted relative to yours?
After all, all of the physical and behavioural evidence you rely on
would be the same whether or not my experience is inverted.
In either case, I’ll call all of the same objects ‘red’.
So, the skeptic reasons, you don’t know that you aren’t in an inverted situation.
And if you don’t know that you aren’t in the inverted situation,
then you don’t know that our experiences are the same.
So you don’t know whether my color experience is like yours.
Inverted spectrum cases are local skeptical scenarios about other minds.
That means the knowledge they question is specific to color experience.
But we can also consider more global skeptical scenarios about other minds.
In a global skeptical scenario, all of your beliefs about other minds would be false.
Suppose, for instance, everyone else in the world is really a robot.
The robots are cleverly programmed, so they behave just as you would
in their situation, but they don’t have any experiences at all.
The skeptic points out that you can’t tell the actual situation
apart from the situation in which everyone else is a robot.
In each case, you have access to your own experiences and
the behavior of others—which appears exactly the same.
But in the robot case, all of your beliefs about other minds are false.
So, since you can’t tell you aren’t in the skeptical scenario,
the skeptic reasons, you don’t know that others have minds at all.
So is the skeptic right?
In the next video, we’ll consider some replies to the skeptic’s argument.