How do we know that we have a mind?
We feel pain. We feel happiness and misery and boredom. We have desires. We believe many things. We plan our actions. We take decisions. We think and speak. We use languages. We are responsive to reasons when we plan and decide. We feel an urge to respond to reasons. We understand and comprehend. We have knowledge. We are aware and conscious and attentive. These are all signs of having a mind.
RenĂ©âŻDescartes, the French mathematician and philosopher, took the use of language to be central to the proof of the existence of a mind. Further, he thought that the signs of having a mind were not compatible with existence as a material object. Indeed, he even thought that no machine ever built could do what the most unlettered human could: reply intelligently to a question. Apparently, nothing made of matter can do this. Another great mathematician and philosopher, G. W. Leibniz, thought that no physical object can perceive. He had an interesting argument for this. He said that if we increased the size of the brain to that of a mill and made a person walk through this space, the only thing to be seen would be parts of its internal structures moving about mechanically. No perception would be in sight.
Descartesâ view is called Dualism. It posits that something entirely different from matter is responsible for what the mind does. But the view ran into a problem noted by a student of Descartes, Princess Elisabeth of Bohemia. Our bodies are physical; the mind is non-physical. How can they interact with each other? Surely, we desire to have ice cream and then eat it. The mind has to push the body to act to get an ice cream. But how can it do so, since the mind is outside of/distinct from the physical order?
An interesting response to this comes from the linguist and philosopher Noam Chomsky, who has argued that an important lesson to be taken from the Newtonian revolution in physics was that we donât really have any conception of the body. After all, gravity is a rather silent and ghostlike presence in the universe. Hence, instead of the ghost in the machine getting exorcised by the new physics, it was the machine that was expelled. The new physics put the ghost firmly in the driving seat. This point about history does not answer the issue of how the mind can affect the body, but tries to suggest that the question has no meaning till we know what a body is. Â
Keeping issues of language or perception aside, it is certainly no easy issue to figure out how any physical thing can be conscious, let alone speak and confer and reason and plan and set goals and pursue what is valuable and good, or the opposite. Even if we are confident and certain â as most cognitive scientists and philosophers are â that consciousness can be accounted for in physical terms, there is much else that needs to be accounted for.  Some philosophers are not even confident of this much. In his book Mind and Cosmos (2012) Tom Nagel has suggested that the prospect of making consciousness come out of complicated bits of matter is not looking great. Indeed, to him it makes no sense at all. He thinks that we have to think quite differently about how causation works in the world in order to make sense of the phenomenon of consciousness.Â
People think â and their thoughts are not just thoughts by a conscious agent, they are thoughts about things in the world. Humans are heavy symbol users. These symbols stand for certain things in the world. This property of thoughts is called intentionality. The names and descriptions we use refer to things in the world. The sentences we use are sometimes true. Reference and truth are semantic properties. The very fact that we can construct sentences is astonishing. That these sentences have some representational content in them and can pass information is equally so.
Enough has been said to suggest that a theory of mind â or of the human mind, if one wishes for specificity â is going to present a formidable challenge. Even if we manage to have a successful account of consciousness, we are going to still leave a lot out. The mind presents two faces: one, there is something to it, separate from its relation to the world; and then there is its relation to the world to account for.
How do we know there is something to it, apart from its relation to the world? Some philosophers and cognitive scientists think that the mind is not a blank slate, a tabula rasa. Humans are born with certain cognitive capacities. Not everything is learnt. It has been noted that the speed with which a child acquires concepts and the facility with which a child begins to understand its mother tongue cannot be explained by any âlearningâ methods. Some innate driving force is necessary.
A good argument for this is given by Chomsky. It might be thought that we learn language by analogy. So, we hear the sentence âAnil ate a bananaâ and when we hear another sentence, like âAnil ateâ, we conclude that Anil ate something or the other, realising that Anil must have eaten something to have âateâ. But this does not always work. Consider the sentence, âAnil is too stubborn to talk to Sunilâ. This means that Anil is so stubborn that he will not talk to Sunil. It is Anil who is refusing to talk to Sunil. Now consider the similar sentence, âAnil is too stubborn to talk to.â By analogy with the earlier sentence, this sentence should mean that Anil is too stubborn to talk to someone or the other. But that is not what the sentence means. Instead, it means, someone or the other is finding Anil too stubborn to talk to. There is a complete âturn-aroundâ of meaning here. This is a remarkable fact. As long as we do not have any empirical, âstatisticalâ, explanation of this, we have to accept that language acquisition is innately driven. An argument like this is called the argument from poverty of stimulus. Similar arguments, as the philosopher and cognitive scientist Jerry Fodor had argued, show that pretty much all concepts are innate. Such arguments are a great problem for any non-nativist account of the mind.
If the mind has some innate structure to it, we need to start thinking about exactly, or approximately, how much. And also about whether the different things that the mind does are served by the same innate structure or different ones. A view, much contested in cognitive science, is that the mind is modular in structure. The mind is like the body in one sense: it has parts just like the body has parts. These parts all do some work of their own. The language faculty is one such part; face recognition is another. Certain parts of the mind, different from these, deal with inputs coming from the perceptual systems we possess. Each part is a faculty or a module. Each part does what it does without reference to the other parts. Each part delivers an output that is usable by other parts.
It appears, then, that a theory of mind is at least a theory of how each part of the mind functions. Of course, having a theory of the language faculty does not tell us much about consciousness, just as a theory of consciousness tells us precious little about how language is acquired. But we need both theories for a good account of what is called âthe mindâ. And we are far from having any idea about how desires and beliefs having semantic features come to interact with the âbodyâ. Philosophers called eliminativists suggest that there are no beliefs and desires. They are like the phlogiston of old. When we get rid of beliefs and desires, we will have a better idea of the mind. Beliefs and desires belong to what is called Folk Psychology.
What we really want are useful idealisations that serve the purpose of informative theories about the various phenomena that comprise the mind. Whether such useful idealisations are possible is the issue. What if no theory really gets off the ground? What does that tell us about the mind? That is a question worth pondering about.