The Extended Mind

Author: Rebecca Renninger
Category: Philosophy of Mind and Language
Word Count: 1000

Can your mind be outside of your body? Normally, we are tempted to think that the mind—including our thoughts, beliefs, memories, experiences, attitudes, etc.—is internal to our bodies. Currently, a number of philosophers challenge this commonsensical view. The view of the mind that these philosophers propose is knows as an extended view, where the mind actually extends out into the world—being comprised not merely of neurons and synapses, but also of objects external to the body. This may initially seem like a radical (or highly improbably) thesis, but views based on it have compelling reasons in their favor.

Inga and Otto

The mind is comprised of mental states and processes. Beliefs are mental states that comprise part of the mind. So, the belief that dogs are mammals is one mental state that comprises part of your mind, along with other things like different beliefs and desires, etc. Compare, for a moment, these two cases.

First, let’s consider a typical case of belief embedded in someone’s normal, biological memory. Imagine Inga. One day, Inga hears that there is an exhibition at the Museum of Modern Art. She decides to go see it. After thinking for a moment, she recalls that the museum is on 53rd Street. So she walks to 53rd Street and gets to the museum. Clearly, Inga believes that the museum is on 53rd Street. She had this belief even before she thought for a moment and consulted her memory. She was not previously conscious of this belief, but we aren’t presently conscious and thinking of many (if not most) of our beliefs at any given time. Like many beliefs, Inga’s belief that the museum is on 53rd Street is simply sitting in her memory, waiting for her to access it. (Did you believe that dogs are mammals before reading this very parenthetical note? Surely you did, even though it was only during and after the reading that you became conscious of your held belief!)

Now let’s consider Otto. Otto suffers from Alzheimer’s disease. Because of this disease, he carries a notebook around with him everywhere he goes. This notebook helps him to get around in the world. When Otto learns new information, he writes it down. When he needs old information, he looks it up. For Otto, the notebook plays the role usually played by memories stored in our brains. Now, just like Inga, Otto hears about the exhibition at the Museum of Modern Art, and decides to go see it. He consults his notebook, which says that the museum is on 53rd Street, so he walks to 53rd Street and goes to the museum.

Just like Inga, Otto went to 53rd Street because he wanted to go to the museum and he believed the museum was on 53rd Street. And, further, it seems reasonable to say that Otto believed the museum was on 53rd Street even before consulting his notebook. Just like Inga, Otto wasn’t previously conscious of the information, it was merely stored waiting to be accessed. Clark and Chalmers assert that “in relevant respects the cases are entirely analogous: the notebook plays for Otto the same role that memory plays for Inga”. The information in the notebook functions just like the information constituting an ordinary non-conscious belief; it just happens that, in the case of Otto, this information lies beyond the skin.1

These authors conclude that we ought not be biased toward the boundaries of skin and skull when it comes to the boundaries of the mind. After all, aside from these boundaries, there is little difference in the roles that an internal belief and an external belief play. These two types of beliefs function equivalently for Inga and Otto in terms of how they guide behavior, etc. What gives a mental state its status as mental is the role that it plays, not its location.

Cognitive Extension

Clearly, not everything in the world is part of one’s mind. So, what does it take for something to be considered mental? First, it must be the case that an individual is coupled to the object that is part of her mind. In order to be so suitably coupled, it must be the case that the item in question be constantly connected to the individual, the information it holds must be directly available, and it is automatically endorsed. Or, the person does not question its reliability. Your smartphone, for instance, might be part of your mind on this account, provided that it is more or less constantly with you, it provides you with information directly, and you don’t question the reliability of that information.2

Is the Mind Really Extended?

One objection to the extended mind thesis is that coupling does not imply constitution. Yes, Otto is closely coupled to his notebook, but that doesn’t mean that it is actually a part of his mind. Devices like Otto’s notebook lessen the demands that we place on long-term memory, but they don’t make up our memory. Even when something is constantly causally connected with another thing, the two do not all of the sudden become one system. Take for example your kidneys. They filter impurities from your blood, and this filtration is thereby influenced by your heart’s pumping blood, your blood vessels, and other parts of your circulatory system. However, the fact that your circulatory system interacts with your kidneys does not make it the case that the filtration of your blood, the activity of your kidneys, takes place within your circulatory system. Filtration merely takes place in your kidneys, which are causally connected to your circulatory system. So, one process may interact with its environment, but that does not mean that that process extends out into its environment.3


The hypothesis that the mind is extended may seem like a radical one. But, there is growing support for the idea that the mind is not simply bounded by our bodies. The question remains, however, whether our cognitive systems are merely causally influenced by external objects or whether these external objects are indeed part of our minds.


1Clark and Chalmers (1998)

2See Clark (2010) Also see Clark (2008).

3Adams and Aizawa (2008). For additional responses see also Adams and Aizawa (2010).


Adams, Fred and Aizawa, Ken. “Defending the Bounds of Cognition.” In Menary, ed. The Extended Mind. Cambridge: MIT Press (2010). pp. 67-79.

———. The Bounds of Cognition. Malden: Blackwell (2008).

Clark, Andy. “Momento’s Revenge: The Extended Mind, Extended.” In Menary, ed. The Extended Mind. Cambridge: MIT Press (2010). pp. 43-66.

———. Supersizing the Mind: Embodiment, Action, and Cognitive Extension. New York: Oxford (2008).

Clark, Andy and Chalmers, David. ”The Extended Mind.” Analysis, vol. 58 (1998). pp 10-23.

Rebecca is a doctoral candidate at the University of Colorado at Boulder. She has a B.A. in philosophy from Davidson College. She is currently interested in philosophy of mind, philosophy of cognitive science, action theory, and free will and moral responsibility. In her free time, she enjoys hiking, cycling, and participating in other outdoor activities in the Boulder area.