Hi, I’m Mason Westfall.
I teach philosophy at the University of Toronto,
and today I want to talk to you about mental states.
Unlike plants and furniture, creatures with minds
have subjective feelings and perspectives that guide their actions.
They have a variety of mental states.
Mental states range from simple feelings like hunger
to complex beliefs about reality.
We can sort these states into five main groups.
Hunger is one of many inner sensations we feel,
along with pain, pleasure, dizziness, itches and others.
Often, our sensations tell us about how things are with our bodies.
If Sarah’s foot hurts, maybe something is wrong.
If she’s feeling tired, maybe she should lie down.
We also have perceptual experiences.
We can see the apple, smell the curry,
hear our friend call our name, and feel Rover’s fur.
Perception tells us about the world.
We know that there are apples on the table because we saw them,
and Sarah believes Michael is mad at her because she heard about it.
So perception can cause us to know or believe things.
We know or believe simple things about our environment,
like that there are apples on the table,
as well as more abstract facts,
like that Ottawa is the capital of Canada.
Knowledge and belief are called epistemic mental states:
they represent the world as being a particular way,
and guide actions.
I go to the fridge because I believe there’s food inside.
To decide how to act, though,
it’s not enough to have epistemic states that represent how the world is.
We also need states of mind that represent how we would like the world to be.
These are called motivational mental states.
Motivational states include simple desires like wanting to eat an apple,
as well as more complicated or abstract goals,
like wanting to get a college degree, or to live in a more just world.
Often our desires are inconsistent,
like the desire to eat healthy and the desire to eat ice cream.
Deciding what to do involves weighing our many desires,
and choosing to satisfy some but not others.
Together, our epistemic and motivational states often explain our behaviour.
If Sarah wants to eat an apple,
and believes that there are apples on the table,
she’s likely to walk over to the table.
We also experience emotions —
simple emotions like happiness or fear,
and more complex emotions like nostalgia, shame or jealousy.
Emotions interact in complex ways with other mental states.
If what Sarah said made Michael mad,
he’s more likely to believe it was wrong.
If going for walks makes Sarah feel happy,
she’s more likely to want to take one.
We often experience positive emotions when our desires are satisfied,
and negative emotions when our desires are not met.
Emotions play an important social role.
We often broadcast our emotions to one another
with facial expressions and other signs.
In doing so, we make ourselves easier to understand,
which in turn affects others’ behaviour.
If Sarah knows that what she did made Michael mad,
she will be less likely to do it again.
So emotions help us communicate,
as well as influence each other.
Different kinds of mental states play different roles in our lives.
It’s striking that we can instinctively attribute these mental states to others,
figuring out how they are likely to interact and cause behaviour.
These abilities — called ‘mindreading’ or ‘mentalizing’ —
constitute a crucial component of social cognition.
The next video takes a look at how humans detect mental states.