1 The questions

Humans have minds, but rocks, pencils and underwear don’t (perhaps luckily). At the same time, mentality seems to come in different degrees of complexity. For instance, cats and dogs seem to have minds, but their minds are presumably much less complex than our own: they can’t formulate thoughts about mathematics, for instance, and for all we know, they are not capable of linguistic understanding.

The main task of Philosophy of Mind is to give an account of the nature of the mental. We approach the issue by asking certain kinds of interesting questions:

• What does it take for something to have mentality? That is, in what circumstances can we attribute something mental properties like being in pain, believing or desiring something?
• What is it to be in a particular kind of mental state? For instance, what is it to be in pain, to have a belief, or to perceive something?
• What is the relationship between the mental and the physical? Mental properties seem radically different from physical properties, as some philosophers have emphasized. So how can the physical and the mental interact? Moreover, some people think that there are only physical things and properties, so that whatever mental properties are, they have to be reducible to physical properties. But if mental and physical properties seem so different, how could the reduction be possible in the first place? How can the mental interact with the physical?

When we’re doing philosophy of mind, we’re not trying to tackle a question about the specific mechanisms by which beliefs are generated, or the process from a beam of light striking your retina to conscious awareness. Those are very important questions, but they are better addressed by science. Part of what we are trying to find out is whether a scientific explanation of mentality can be given, and if so, how. This may be initially hard to understand, but as you read more philosophy, you will come to understand the kind of explanations that we’re after.

1.1 Mental phenomena

There are different kinds of mental phenomena. In this course we will focus on two:

Intentional states:

Mental states that are about something. For instance: beliefs, desires, knowledge, etc.

Phenomenal states:

Mental phenomena that involve sensations, or a certain way it is like to have them. For instance, if you look at a sunflower, there is a way it looks like to you: it looks yellow, and this way of looking is part of your visual experience. When you bite a peach, there is also a certain way it feels like: sweet, perhaps a bit sour, a certain kind of raw feeling.

2 Basic metaphysical notions

Substance:

Some people may define a substance as something that can exist independently of other things. For instance: chairs, tables, people, and particles are substances. Shadows, smiles, laps, and hallucinations, are not substances. A quick, perhaps defeasible, test to see whether something is a substance is this: if we can conceive of a possible situation in which only x exists, then x is a substance; otherwise, x is not a substance.¹ For instance, we can conceive a situation in which only a chair existed, or one in which only a particle existed, but we can’t conceive of a situation in which only a smile existed.

Properties:

Properties are qualities that substances can have. For instance, my mom’s cat has the property of being spotted, and right now you have the property of reading the lecture notes. When we want to say that something has a given property, we often say that that thing instantiates the property, or that it exemplifies the property. In general, we will use the variable F for properties, as a way of talking about an arbitrary property.
Not only substances can have properties. For instance, philosophers often think that properties themselves can have properties: for instance, the property of being red has the property of being instantiated—this is so because there is at least one thing which is red. Properties like redness, having a belief, experiencing pain, etc., are usually called first-order properties. Properties of properties are usually called second order properties, but for now we can only worry about the first order properties.

Relations:

Presumably, you are in New York as you read these notes. That means that you stand in a certain property with the city of New York. This is the relation of being in. You may stand in this relation to other places, like Chicago, Boston, or Mexico City. You may stand in different relations to different objects.

States, events, processes:

Think of a computer. At the very least, it has two states: on and off. We can see the passing from one state to another as an event. For instance, when you turn on your computer, there is an event of your computer chaging from the state OFF to the state ON. We can see a process as a series of states and events that are causally connected. For instance, the process starting with your computer being OFF, its change of state and the final state ON is a process. In most cases, the states, events and processes that we care about are much more complex than this, but you get the idea.

Ontology:

Ontology tries to answer the question what exists. There are two uses of the expression ‘Ontology’. One is as the study of what exists, or what there is. The other is as a special commitment of a theory as to what exists. For instance, we say things like this “Contemporary physics is committed to an ontology of particles”, or we say that physics has particles in its ontology. What we mean is that if the sentences that constitute physical theory are true, then particles must exist (roughly). In this course, we commit ourselves to an ontology including substances, properties, states, events and processes, but which substances, properties, etc. in particular we should be committed to is a matter of controversy. Hopefully, by the end of the course you will have made up your mind as to what ontological commitments you want to take on board when it comes to the nature of the mental.

Supervenience:

A supervenes on B if and only if there can be no difference with respect to A without a difference with respect to B. Equivalently: A supervenes on B just in case if everything remains the same with respect to B, then it also remains the same with respect to A.

Some philosophers think it’s a mistake to talk about minds as if they were substances. Instead, some of these philosophers prefer to talk about mentality as a more general phenomenon. Something is said to have mentality if it has at least some mental property—for instance, if it has some beliefs, conscious experiences, or any other kind of mental state. Thus, for these people, having a mind is not like having an iron pan or a punching bag. Rather, having a mind is more like having a property.

3 Mind-Body Supervenience

When someone says that the mental supervenes on the physical, she might mean any of the following:

Generic SV:

Any two things that are exactly alike in all their physical properties must be exactly alike in all their mental properties.

Strong SV:

If anything x has a mental property M, there is a physical property P such that x has P, and necessarily any object that has P has M.

Global SV:

Any two worlds that are exactly alike in all physical respects are alike in all mental respects as well.

For our purposes, the generic version will do.

3.1 Physicalism

Physicalists are usually described as thinking that all entities that exist are either things recognized by fundamental Physics, or reducible to things that are so recognized. One way to understand the relevant notion of reduction is by means of one of the supervenience thesis we presented above. Physicalists want to claim that all the mental properties a given object may have are metaphysically determined by the physical properties it has—though as we’ll see in a bit there are many possible formulations of physicalism, and which one is the best and most satisfying formulation is a matter of controversy.² At the very least, our generic formulation of supervenience is a claim that every physicalist is committed to. Here are some more substantive formulations of physicalism, all of which accept some version of the mind-body supervenience:

Substance Physicalism:

The only kinds of substances that exist are physical substances. Any substance is either a minimal such substance or an aggregate of some such substances.

Nonreductive physicalism (property dualism):

Mental properties are distinct from and irreducible to any physical properties.

Reductive physicalism:

Psychological properties are either identical or reducible to physical properties.

4 Looking for the mark of the mental

4.1 Epistemological criteria

Direct knowledge:

Direct knowledge doesn’t rest on evidence. Kim also describes it as being a sort of non-inferential knowledge (knowledge that doesn’t rely on an inference). For instance, you don’t seem to infer your knowledge that you’re experiencing great pleasure as you bite a juicy mango. Unfortunately, this doesn’t seem like a good candicenter for a mark of the mental, since we seem to have direct knowledge of some physical facts. For instance, you seem to know directly that there is a computer in front of you (or a piece of paper, if you’re reading this from a hard copy).

Privileged access:

If you are experiencing some sort of mental state, it’s tempting to say that only you can know it the way that you do. You know it from the inside, so to speak. Others may come to know that you are in that mental state if they examine your brain or something like that, but only you can know it directly. Unfortunately, there are other things that we seem to be able to know in a privileged way, but are not mental phenomena: for instance, the position of our limbs.

Infallibility and Transparency:

Infallibitlity: if you believe that you are in a certain mental state M, then you are in mental state M. Transparency: if you have a certain mental state M, then you are aware that you have such state. Can you think of any mental phenomena that are not transparent or with respect to which we are not infallible?

4.2 Intentionality

People call intentionality the feature of being about something, or being directed. For instance, your belief that the sun is shiny is about something: the sun. But we can also have mental states that are directed towards things that don’t exist: some people wish to find their true love, or the fountain of youth. It makes sense to desire those things, but it doesn’t make sense to kick, pull or eat something that doesn’t exist. What do you think? Do all mental states exhibit intentionality?