The Extended Mind 1. The Extended Body: We often have no problem accepting that the body can be augmented or extended in certain ways. For instance, it is not so far-fetched to think of someone s prosthetic limb as being an extension of a PART of their body. For a blind person, a cane can be an extension of their body; a truly great musician will often claim that their instrument is a part of them; they become one with their instrument. But, what if the mind is like that? That is, what if the mind extends beyond the brain? 2. The Extended Mind: We manipulate the world in order to aid and augment some cognitive processes all the time (call this an epistemic action). We use scrap paper (or our fingers!) to figure out tough math problems, we write down important things so that we can remember them, and so on. Now, imagine that you are asked to determine how various shapes ought to be rotated and arranged in order to form a perfect square: You solve this puzzle in three different scenarios: (a) You perform the rotations in your head in order to figure it out. (b) You are given the option to either figure it out naturally in your head or use a neurally implanted computer chip which you can operate with your brain to visually rotate each shape inside your head. (c) You are given the option to either figure it out naturally in your head or use an external computer, pressing keys to manually rotate each shape on a screen. 1
It is uncontroversial that solving the puzzle the old-fashioned, in your head way involves a cognitive process of your mind. In that scenario, you consciously manipulate the world in such a way as to solve it namely, your brain. Now ask: Are the processes that occur in (b) and (c) a part of your mind s cognitive processes? If not, why not? Privilege brain-matter? After all, when you use a computer that is inside your head (b), you are ALSO consciously making a decision to manipulate some part of the world in order to solve it only, the stuff inside of your head that you are manipulating is not organic brain matter, but rather a computer chip. So, is the BRAIN, or CARBON somehow privileged over, say, SILICON? There doesn t seem to be any good reason for such discrimination. [Or is there? Do you agree?] Privilege the inside of the skull? Furthermore, the only difference between (b) and (c) is the LOCATION of that computer namely, OUTSIDE of your skull, rather than inside. So, is the location INSIDE of the skull somehow privileged over those locations that are outside of it? This doesn t seem like a justifiable discrimination either. [Do you agree?] But, once we reject the claim that there is are no good reasons to insist that (i) the material of the mind is restricted to organic brain matter, or that (ii) the location of the mind is restricted only to those locations inside the skull, an interesting thesis arises: The Extended Mind Thesis. This thesis is the first premise of the following argument: 1. The Extended Mind Thesis: If, as we confront some task, a part of the world functions as a process which, were it done in the head, we would have no hesitation in recognizing it as part of the cognitive process, then that part of the world is part of the cognitive process. 2. Your iphone functions in such a way. 3. Therefore, your iphone is a part of your cognitive process (i.e., your mind). 3. Objections: Here are some worries: 1. The mind is conscious. But, your iphone is not conscious. Reply: Surely, there are many non-conscious cognitive processes that are uncontroversially a part of your mind. 2. The mind is portable. It goes with you wherever you go. But, the external world does not. 2
Reply: Even if this were a requirement for something to be a part of your mind, we could still include things like your iphone as a part of your mind, since it too is portable, and reliably goes with you wherever you go. 3. Even if we admitted that some COGNITIVE PROCESSES occur outside of the head, this does not entail that the MIND is outside of the head. Reply: Consider the following two stories: Inga: Inga just heard that the new Star Wars movie came out today. She forms the desire to go see it. She thinks for a moment and recalls that the movie theater is in New Town. She goes and sees the movie. Otto: Otto suffers from Alzheimer s disease. He has trouble forming new memories. He carries around a notebook where he keeps important information that he wants to remember. Otto has just heard that the new Star Wars movie came out today. He forms the desire to go see it. He consults his notebook and it says that the movie theater is in New Town. So he goes there and sees the movie. Now, clearly Inga believes that the proposition <The movie theater is in New Town> is true. Furthermore, she believes this BEFORE she consults her memory. Surely, we do not want to say that people only believe things that they are CURRENTLY thinking of. (Call these occurrent beliefs.) Admittedly, her belief is not an OCCURRENT belief. We might instead call it a dispositional belief i.e., she is DISPOSED to report that she believes this proposition when asked. But, ask yourself: Do you have beliefs that you are not currently thinking of? E.g., don t you believe that you live in Williamsburg, that you are a human being, and so on, even when you are not consciously thinking about these beliefs? So, Inga s beliefs are stored in her brain and beliefs are a part of the mind. But, the two cases are completely analogous except for the fact that Otto must consult a notebook instead of his brain. So, it seems that Otto ALSO believes that <The movie theater is in New Town> even BEFORE he consults his notebook. So, Otto s beliefs are stored in his notebook and beliefs are a part of the mind. Therefore, a part of Otto s mind is in his notebook. The alternative is to say that, at best, Otto believes that the movie theater is wherever his notebook SAYS it is. But, then, in Inga s case, we would have to say that, at best, she merely believes that the museum is wherever her memory has recorded that it is. But, this doesn t seem to be what she believes. Or at least, that is not ALL she believes. Imagine if I asked you, Do you believe that you live in Williamsburg? and you replied, I m not sure. I only believe that I live wherever my memory tells me I believe. Hold on. [consulting memory] Yes, now I believe that I live in Williamsburg. That is absurd. 3
Chalmers says this is one step too many. For simplicity, we should just cut out this middle-man. He writes: The moral is that when it comes to belief, there is nothing sacred about skull and skin. What makes some information count as a belief is the role it plays, and there is no reason why the relevant role can be played only from inside the body. Rebuttal: We might insist that there are relevant disanalogies between Inga and Otto s case, which entail that Inga has the non-occurent belief but Otto does not: Inga s belief is in her head, but Otto s is outside of his head. Reply: We cannot simply STIPULATE this. That is begging the question i.e., assuming to be true the very claim that is being debated. Inga s belief stays put. It is reliable, and doesn t come and go as Otto s notebook might. It would seem odd to say that Otto only has certain beliefs when he is carrying his notebook with him, but that he forgets things when he accidentally leaves it at home. Reply: But, Inga s beliefs don t really stay put either. The come and go when, e.g., she is sleeping, or intoxicated. As long as they are reliably there under certain conditions e.g., when she is awake, sober, parts of her brain are not removed by an evil neuroscientist, etc. then we can still attribute non-occurrent beliefs to her. Similarly, as long as Otto s beliefs are reliably there under certain conditions e.g., when he is awake, sober, his notebook is with him, etc. then we can do the same for Otto. Otto s belief is gained by PERCEPTION (i.e., LOOKING AT his notebook). Meanwhile, Inga s belief is gained by INTROSPECTION (i.e., looking INWARD, mentally). Reply: But, the phenomenological FEEL of retrieving a belief, memory, etc., does not seem important. We might imagine a being who has to use his EYES to recall memories, form occurrent beliefs, etc. (Chalmers mentions The Terminator as being portrayed in this way.) Conclusion: Unless you want to deny the existence of non-occurrent beliefs, then we must accept that Otto s mind extends into his notebook. In short, the mind ain t all inside of the head! 4
4. Some Implications: The Extended Mind Thesis is not just an interesting philosophical thesis. If true, it may have some surprising implications for the way we view the world: Exams test your mind s ability to figure out problems, etc. But, if the external world is a part of your mind, then ought exams be open-book, allow calculators, computers, etc.? Some say that google is making us stupid. But, if the Extended Mind Thesis is true, then isn t it really making us much smarter? After all, it vastly extends our access to knowledge. If your mind extended, and your self exists wherever your mind exists, it follows that your SELF is extended into the world too. You are not just your body, but an extended SYSTEM that reaches out into, and is intermingled with, the external world. Whoa Dude On a related note, if parts of the external world are parts of your mind, then destruction or theft of those things is very serious. They are a destruction or a theft of a part of your mind! If I steal your iphone, it is as invasive as if I have gone into your mind and erased some of your memories, etc.! This pairs with the previous point nicely. It is not uncommon for a couple who have been together for decades to finish each other s sentences, to serve to fill in the gaps in each other s memories, etc. What is more, when one of them dies, it is not unusual for the remaining partner to say, I lost a part of myself that day. For more, see Chalmers TED talk on this subject, here. 5