The mind Body problem

6th October 2020

Abbreviations and terminology

  • TYIT: Type Identity Theory
  • TOIT: Token Identity Theory


From On the method for distinguishing real from imaginary phenomena:

Ab actu ad potentiam valet consequentia

If something exists, it means it’s possible.
I am sure of phenomena, which are what I perceive, what I think exists for sure in my thoughts. Which phenomena actually exist in the outer world?

We can consider the phenomenon itself or a relation of phenomena. A phenomenon is real if it is…

vivid, complex, and internally coherent (congruum: consistent in itself). It will be vivid if its qualities, such as light, color, and warmth, appear intense enough.

The idea of “vividness” to describe perceptions recalls Hume’s definition of impressions: apparently he studied by Leibniz, too; an object is made real by different and varied sensory experiences.

Different phenomena are real if their relation is consistent. There should also be a consistency in time: if we can predict a behavior, we can prove reality.

And all of this was a dream, we should call it reality, since it’s consistent, I can’t prove its non-existence. We can't prove the existence or non-existence of the world. We have only a moral certainty, not a metaphysical one.

Coherence of the same experience and coherence with other experiences. If I live in a dream which is coherent in itself, I have the right to call it reality.

Through reasoning, we can attempt to include new events and experience in reality, and to describe it.

It’s impossible that only on substance exists, other finite beings exist, yet not all the possible beings do.

If our life were a dream, we can’t accuse God of being a deceiver. We are deceived not by God, but by our judgment. We should be thankful to God for making phenomena coherent among each other.

7th October 2020

The body-mind problem emerged after the Second World War, in the 50s; Philosophy of mind emerged to satisfy the need to find tools to substitute or improve human mind.

What is the mind?

  • Dualism: mind and body exist as different separate entities (Plato, Descartes, Leibniz). The mind is spiritual, the body merely is material
  • Monism
  • Tempered Monism

!Second meditation

The existence of the self

According to Aristotle, since we know everything through experience, we should be able to know our minds by first being able to know the world; three kinds of soul:

  1. Vegetative faculty: growth (plants)
  2. Sensitive faculty: motion (animals)
  3. Rational faculty: intellect (humans)

The higher functions carry out the lower ones, there is some sort of hierarchy; an abstraction through sensory material

The corresponding faculties in Descartes are the body and the mind alone

Self-perception is a way of knowing the body (anticipation of the 6th meditation). We don’t only know we exist, we now know we are a thinking thing.

The broad meaning of thinking

I use this term [‘thought’, ‘cogitatio’] to include everything that is within us in such a way that we are immediately conscious of it. Thus all the operations of the will, the intellect, the imagination and the senses are thoughts. I say ‘immediately’ so as to exclude the consequences of thoughts: a voluntary movement for example, originates in a thought but is not itself a thought.

Descartes’s Second Set of Replies to his Meditations

Descartes is strictly connecting the domain of thinking, consciousness with the domain of mind. Descartes is the first to identify consciousness (conscientia) with mind (mens). Before him, is only had its ethical meaning, the tool to define right or wrong. In contemporary philosophy, they’re used as synonyms.

12th October 2020

The meaning of substance

The substance isn’t linked to the individual. In Aristotle, every being is a substance. Substance is extension: bodies are different modes of one substance.

By substance we can understand nothing than a thing which exists in such a way as to depend on no other thing for its existence.

The existence of the “I” is proved since it depend on no other thing. Therefore, it’s a substance.

The proper sense of substance belongs only to God:

And there is only one subject which can be understood to depend on no other thing whatsoever, namely God.

From here, Spinoza’s definition of God.

Proving the existence of substance

We can, however, easily come to know a substance by one of its attributes, in virtue of the common notion that nothingness possesses no attributes, that is ti say, no properties or qualities.


To each substance there belongs one principal attribute; in the case of mind, this is thought, and in the case of body it is extension.

A substance may indeed be known through any attribute at all; but each substance has one principal property which constitutes its nature and essence, and to which all its other properties are referred.

Then, the “I” is proved through the attribute of thinking. The substance is independently proved to exist.

Self perception means to have the mental property, it’s not a physical activity of the body.

In the second part of the second meditation, Descartes provides a counterargument to the common belief that since childhood, as newborns, we learn through the senses. Also the knowledge we define “sense perception” doesn't belong to the body, but to the mind.

It seems that sensory experience is easier to accept, the empirical level of knowledge is easier.

From an empirical approach: a body has several properties, which make me understand what it is. Nevertheless, those properties can change: the example of a piece of wax. Then, it’s the mind which is able to state it’s it.

There are infinite possibilities and ways a thing can change, thus it’s not a product of imagination, since it will never be able to encompass it

A distinction between a confusing intellectual knowledge, derived from the senses, and a complete knowledge, from a purely mental scrutiny

My sensory experience is possible, it’s meaningful, only because there is a mind which collects and organizes the data received from the senses

We always use our mind, also when we believe we’re using the senses.

Even with Physics, even when talking about atoms, it’s our intellect which allows us to understand the kink which bonds ice and water, knowing the matter is the same, yet the status is different. It’s thanks to our mind we know it’s always H2O.

The “enemy” of Descartes isn’t the belief that science doesn’t need empirical data, but the aristotelian idea that knowledge comes from the senses only. The point Descartes wants to prove is that science necessarily needs the mind to form theories.

!Sixth Meditation

3rd November 2020



Mind and body are different and separate, but they interact. E.g. a physical stimulus corresponds to a stimulus to the mind. In the Sixth Meditation: the mind and the body are strictly entangled.

Descartes was both a dualist and an interactionist

How can the mind exist separately from the body?
According to Descartes, it’s sufficient to explain the real distinction.

What does it mean to die? Our individual body is destroyed, but the mind will continue to exist, as well as matter in general.

The main act of thinking is being conscious of something: if I knew how the knowledge of the external comes to me, I’d be conscious of it.

Note: we’re speaking about the demonstration of the existence of bodies, not their nature.

Sensory experience is truthful only in the case of understanding the existence of the bodies.

Leibniz: we can only have a “moral certainty” the external world exists, we have no necessary and logic knowledge of it.

Both parallelism and occasionalism deny interactionism.

Both of them state that to each mental event corresponds a physical event. The difference between them is in the power they give to limited entities, finite substances.


Mind and body are two clocks created at the beginning of time. Events occur simultaneously in both because God pre-programmed the same occurrence in the two entities.

Leibnitz: the causal power is in substance: each monade is an entry of an encyclopedia, in which is stores all the data about the events which will happen to it. The monade is the cause to all its events. The body of the monade is synced with its essence. There is no free will, but there is freedom of spontaneity (we are free in the principles of our actions. What we do is inside us. Compatible to determinism), not “Freedom on indifference” (nothing drives your actions). Each monad as an “Encyclopedia entry”, which contain all the info and data about it across its life. To be free means not to be constrained by the principle of not contradiction. To be free means not to be tied with logic.


God established laws for which every time I want to raise an hand, my body will raise an hand. To each physical state corresponds a mental state, predefined from God.
Substances have no internal power at all

The causal power is only in God.

Why mental states cannot cause physical states +++ min 51 (epiphenomenalism)

There are a lot of monists even before the 21st century.


Psychological theory of the mind: the only scientific way to explain mental states is through apparent behavior. Behaviorism wants to make psychology a science. The most important psychological school in that period (beginning of 20th century) was freudianism. In what way can we understand the mind to make it scientific? Behavior. If we analyze behavior, we can understand the mind.

Behaviorists started to follow the suggestions of philosophy of mind, which sustained the non-existence of the mind: monism. Physical changes in our mind. Ryle confuted Descartes by saying he used behaviorism by applying it to the new philosophy of language, which was very important in England in that period. Philosophy of language is the mother of Philosophy of mind.

Behaviorism refutes both monism and dualism: it denies the existence of the mind altogether.


  • The difference between actually being in a certain condition, so actually feeling something, and pretending to be so.
  • Behaviorism completely fails to explain qualia, or how it actually is to be in a certain state, feeling something. It reduces a feeling to what appears from it, ignoring the force of the experience on the self.
  • Self perception becomes the same as perception of the others’ behavior. A counter-reply may be that we acquire our own beliefs by envisioning how would we react to a certain event.

Philosophy of Language

a discipline which links all philosophical problems to language. To solve philosophical problem, we need to solve linguistical issues. Those issues can be solved with the therapy of language. Which is the noun, which is the adverb, which is the predicate. We have a linguistic framework which is responsible for our philosophical conceptions of the world.


  • in Descartes: mens instead of anima, because the latter was too similar to animus, which seemed too material.
  • “Reality” - “existence”. Unicorn is a real object which doesn’t exist.

Mental events are physical events, mental states are physical states.

Both are two forms of Physicalism.


Type Identity Theory

Each physical state of a particular type is a particular state of a particular type. A state of the brain corresponds to a thought.


A type is some replicable entity;

an abstract category or class of linguistic item or unit, as distinct from actual occurrences in speech or writing.


  • we can imagine the same mental event as caused by different states of the brain; subjective or individual interpretations are harder to be explained. Thoughts should be neatly divided and very clearly distinct, while they are not.
    E.g.: two people may both think of Descartes, but one refers to him as the author of the Meditations, while another one refers to him as the author of the Principles. Both are thinking about the same person, but in two different ways. Thus, the same thought, yet two different states of the brain.
  • Nagel’s criticism: there is a set of experiences connected to consciousness (feelings, love, sadness) which we can’t describe as mere physical states. They are qualitative, qualia. Consciousness can’t be reduced to a physical states. Even if our
  • no deep understanding of mental activities: if to any mental state corresponds a thought which we intimately and completely know corresponds an identical mental state, why can we understand one while the other not?
  • Size, location and shape: if a thought is physically represented, it should have a precise location in our brain, and at the same time it should be supposed to acquire some shape, but we have no perception of this.

TOken Identity Theory

Different states of the brain can produce the same mental event:


A token is a particular instance of a type;

an individual occurrence of a linguistic unit in speech or writing.

While the type is the species, the token is the individual instance of the species.


If two people are experiencing the same brain condition, they are necessarily thinking of the same thing

4th November 2020


Mental states can’t be described exclusively by physical properties, they must be identified by what they do. Mental states are the relationship between inputs and outputs.

Consider the mind as a software and the brain and the body as the hardware.


A strong argument pro AI: whatever kind of reality can provide a mental state.
Computational functionalism: our mind calculates different inputs and produces different outputs. A not so recent point of view, Hobbes shared it.

Contemporary functionalists may consider Aristotle as their predecessor.

Turing Machine

A mathematical tool to test the understanding of a machine. Considering every kind of symbolic process, everything can be described through a mathematical process.

The mind conceived as a Turing Machine, it performs calculations. Mind is something natural, it doesn’t belong to a different reality.

Can a machine think?

According to Turing, we should ask ourselves: can a machine trick us? Can the machine trick a man it’s not a machine interacting with him?

It is played with three people, a man (A), a woman (B), and an interrogator (C) who may be of either sex. The interrogator stays in a room apart from the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman. He knows them by labels X, and Y, and at the end of the game he says either “X is A and Y is B” or “X is B and Y is A.” (…) We now ask the question, “What will happen when a machine take the part of A in this game?” Will the interrogator decide wrongly as often when the game is played like this as he does when the game is played between a man and a woman? These questions replace our original “Can machines think?

~ A. Turing, Computing Machines and Intelligence, Mind, Vol. LIX. No. 236 1950

Touring test on Wikipedia

If a computer can fool a man by simulating humanity, therefore a computer actually it thinks. How? By answering in a meaningful way through questions

Is it possible to imagine a situation like this?

There are a few software in history which passed this test, one of them is Eliza, whose name comes from Shaw’s play Pygmalion.

According to computational functionalism when we elaborate something, we are calculating, and mental processes are calculations. We can answer the original question if we can create a machine which can manipulate symbols in the same way a human does.


The Chinese Room

A thought experiment by John Searle:

I have a room full of symbols which I don’t understand, yet I have a set of tools in my language which guide me through the steps I have to deal with. I follow those steps without having any idea of what symbols mean or refer to. If I do this, I’m not thinking.

Suppose that I’m locked in a room and given a large batch of Chinese writing. Suppose furthermore (as is indeed the case) that I know no Chinese, either written or spoken, and that I’m not even confident that I could recognize Chinese writing as Chinese writing distinct from, say, Japanese writing or meaningless squiggles. To me, Chinese writing is just so many meaningless squiggles. Now suppose further that after this first batch of Chinese writing I am given a second batch of Chinese script together with a set of rules for correlating the second batch with the first batch. The rules are in English, and I understand these rules as well as any other native speaker of English. They enable me to correlate one set of formal symbols with another set of formal symbols, and all that “formal” means here is that I can identify the symbols entirely by their shapes. Now suppose also that I am given a third batch of Chinese symbols together with some instructions, again in English, that enable me to correlate elements of this third batch with the first two batches, and these rules instruct me how to give back certain Chinese symbols with certain sorts of shapes in response to certain sorts of shapes given me in the third batch. Unknown to me, the people who are giving me all of these symbols call the first batch a “script,” they call the second batch a “story,” and they call the third batch “questions.” Furthermore, they call the symbols I give them back in response to the third batch “answers to the questions,” and the set of rules in English that they gave me, they call the “program”.

Suppose also that after a while I get so good at following the instructions for manipulating the Chinese symbols and the programmers get so good at writing the programs that from the external point of view-that is, from the point of view of somebody outside the room in which I am locked-my answers to the questions are absolutely indistinguishable from those of native Chinese speakers. Nobody just looking at my answers can tell that I don’t speak a word of Chinese.(…) As far as the Chinese is concerned, I simply behave like a computer: I pet form computational operations on formally specified elements. For the purposes of the Chinese, I am simply an instantiation of the computer program.

J. Searle, Minds, Brains, and Programs, from The Behavioral and Brain Sciences Vol. 3

If we consider thinking as an activity which only manipulates symbols through a set of instructions, we are describing thinking in a form which is opposite to what we believe: thus to be conscious by understanding the meaning of we’re manipulating.

To think, we need to semantically understand the meaning of what we’re doing. The mere manipulation of symbols isn’t enough.

The most important feature of consciousness is intentionality: the capability of understanding the element which brings meaning to a symbol. Every semantic relationship, when thinking, has to involve an understanding, an intentional relationship. To Searle, this is a biological function. The substratum is important. It’s not possible that a different substance will realize the same processes that we realize with our mind.

Is intentionality close to the meaning given by Hume when he speaks bout matters of fact?

Conscious processes are qualitative effects of effects of lower level processes, so neuronal processes, which give births to higher processes which are mental states.

Searle refuses to be a dualist, since he believes mental states aren’t a different kind of reality. This just means we can’t reduce mental processes just to physical events. The mind has its own semantic dimension.

The China Brain

A.K.A. the The Chinese Brain or The China Gym

Imagine the whole population of China acting as neurons and the country as a huge replication of a brain: the whole country, thus the brain, can’t have consciousness. We can’t reduce mental processes to the mental level of neuronal triggers brains contain.

Daniel Dennet believes that the whole nation of China actually thinks. He admits anything +++.

Freedom can be explained with a deterministic system. Freedom and consciousness are precisely the outcome of evolution: Freedom evolves (2003) a book in which consciousness and freedom must be considered as an outcome of our evolution

David Chalmer +++

Consciousness is thus something more than physical entities.

Next topic: Personal identity



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