Extended Mind Redux: A Response

Extended Mind Redux: A Response
By ANDY CLARK

Thanks to all who read and commented on my recent Stone post, “Out of Our Brains.” Lots of interesting, challenging, and important issues were raised, but I’d like to react very briefly to just a few recurring themes, and to add one important, and accidentally omitted, note of thanks.
The thanks (and see comment 73) are to professor David Chalmers. Dave was co-author of my original 1998 paper “The Extended Mind,” and is the sole author of a wonderful foreword to my 2008 book, “Supersizing the Mind.” Dave had a big hand in the original paper. Everyone who asked about the thin line between tools and extensions, or about the vexed question of extending the conscious mind, should read his recent forward, too.

Themewise, I was struck by the somewhat remarkable fact that about half the commentators thought the general line about extending the mind was plausible and even obvious, while about half thought it was implausible and perhaps even self-evidently false. In optimistic mode (which I mostly am) I take this as a good sign: as suggesting that there is indeed something worth thinking about here. If I were feeling less upbeat, I might take it as a sign that I just hadn’t made the thought clear enough. A couple of comments made me worry on that score, so a few clarifications seem in order.

I didn’t mean to downplay the pivotal role of the brain/body in human thought and reason. I can indeed survive the loss of my iPhone but not the loss of my brain! But as Dave Chalmers has pointed out, I can also survive the loss of my finger, the loss of a few neurons, or even the wholesale ablation of my visual cortex. It does not follow that e.g. my visual cortex, when all is up and running normally, does not constitute part of my cognitive apparatus. This reveals something important. It is only when you turn up the magnification, seeing the biological agent as herself a kind of grab-bag of distinct circuits and capacities, that the possibility of true cognitive extension even becomes visible. That possibility then takes shape as the possibility that some non-biological circuitry (connected by various forms of looping interaction to the biological core) might become sufficiently integral to some of my cognitive performances as to count as part of the machinery of mind and reason.

This talk of the machinery of mind is important. A few commentators rightly suggested that mind itself is probably not a “thing” hence not worth trying to locate. That is not to say — heaven forbid — that it is a non-material thing. Rather, it might be a bit like trying to locate the adorableness of a kitten. There is nothing magically non-physical about the kitten, but trying to fine-tune the location of the adorableness still seems like some kind of error or category mistake. In the case of mind, I think what we have is an intuitive sense of the kind of capacities that we are gesturing at when we speak of minds, and so we can then ask: where is the physical machinery that makes those capacities possible? It is the physical machinery of thought and reason that the extended mind story is meant to concern.

A couple of replies touched on what is really one of the philosophical hot potatoes here, which is the distinction between “mere” inputs to a cognitive system and elements of the system itself. Critics of the extended mind (for example, Fred Adams and Ken Aizawa, in their 2008 book called “The Bounds of Cognition”) think theorists of extended cognition are guilty of confusing inputs to the cognitive engine with stuff that is part of (and “constitutes”) the cognitive engine. I think this distinction between “mere” inputs and processing elements in far less clear than it sounds. An analogy I sometimes use is with the workings of a turbo-driven car engine. Compare: the car makes exhaust fumes (outputs) that are also inputs that drive the turbo that adds power (up to around 30 percent more power) to the engine. The exhaust fumes are both outputs and self-generated inputs that, as they loop around, surely form a proper part of the overall power-generating mechanism. I think much the same is true of our use of bodily gestures while reasoning with others, and of the way that actively writing contributes to the process of thinking. The gestures and words on the page are outputs that immediately loop back in ways that form larger circuits of ongoing thinking and reasoning.

Some respondents raised important and interesting questions concerning conscious experience. I note only that my own account of cognitive extension is not meant to make any claims extending the machinery of consciousness beyond the brain. I myself am skeptical of such extensions. But some excellent philosophers (like Alva Noë in his 2009 book, “Out of Our Heads”) do go that far, and I would refer those interested in this issue to that short and accessible treatment.

Finally, special thanks to all those who suggested sci-fi books, or other stuff that I ought to be reading. My holiday stocking (and perhaps my mind) will be greatly expanded as a result.