A partial index of discussion notes is in http://www.cs.bham.ac.uk/research/projects/cogaff/misc/AREADME.html
The letter was provoked by my reading a letter to the New Scientist
by Andy Clark
and Daniel Dennett, published on 13th December, and available online here.
That letter was a response to
letter by Mario Beauregard and Jeffrey M. Schwartz,
which, in turn was a reaction to an article by Amanda Gefter, published on
22 October 2008, entitled 'Creationists declare war over the brain'.
From: Aaron Sloman To: New Scientist Date: 15 Dec 2008 Dear New Scientist, In the letters page of New Scientist 13th Dec., Andy Clark and Daniel Dennett criticise the leap from the existence of non-material causes (e.g. in minds) to religious or anti-scientific dualist conclusions. They rightly challenge the apparent assumption by Mario Beauregard and Jeffrey M. Schwartz that thoughts, attending and mental activity are not realised in material substance. Unfortunately, for most people the notion of mental phenomena being "realised" in material substance is incomprehensible -- as much mumbo-jumbo as talk of spiritual substances is to materialists. In my experience it is very hard to get people who lack a deep appreciation of important developments in computer science and engineering in the last half century to understand how such realisation is possible. A first step is to make them pay attention to the non-material processes that they interact with in their computers every day, e.g. playing a computer game, or using a word-processor running in the computer with the mysterious ability to manipulate fonts, characters, words, line-lengths and paragraph formats, and even correct spelling mistakes, despite the fact that opening a computer and inspecting it with the most powerful microscopes, physical measuring devices or chemical tests, reveals only physical mechanisms, and no fonts, characters, words, paragraphs, etc., and not even numbers, calculations, or programs. What is not generally understood is that as a result of very complex collaborations between scientists, engineers, mathematicians and logicians it has been possible to create physical machines of a very special kind, namely with the ability to support the operation of what have misleadingly been labelled 'virtual machines' running in them and performing a very wide variety of non-physical tasks. The label 'virtual' is misleading because these are unlike 'virtual reality' systems that merely represent other things that do not exist (e.g. non-existent people walking around on non-existent planets). In contrast entities, events and processes in virtual machines not only exist but can cause events and processes both in virtual machines and in physical machines -- for instance when the actions of a spelling checker cause the physical patterns on your computer screen to change because an error has been corrected. All this is possible only because of a host of developments over several decades, involving electronic devices of many kinds with complex interfaces between them, along with software and hardware components performing memory management tasks, interrupt generation and handling hardware and software, device drivers, operating systems, compilers, interpreters, filesystem managers, garbage collectors, network protocol handlers, and many more. A key feature of all this design work is to ensure the simultaneous truth of a complex network of conditional statements relating what would happen if so and so occurred in physical or virtual machines. The support for that network of truths is equivalent to support for a complex web of causal connections. As a result of all this, multiple virtual machines of different kinds can coexist and interact in a single physical computer, even a computer with only one CPU. Virtual machines were originally designed to make the processes of design, development, modification, extension of complex systems easier for human engineers, because of the intractable complexity of performing those tasks by thinking about all the physical structures and processes involved (millions of transistors changing their state millions of times a second, and even more electrons flying around the connectors). What is now clear is that the use of virtual machines, can, for the same reasons, make it much easier for machines to monitor and control themselves. If they had to observe and modify the operations of all the millions of rapidly changing physical components the task would be impossible. Instead, the controlling virtual machines monitor and modulate behaviours of virtual machines, or components of virtual machines. This can also enable some computing systems to discover and report faults, detect intruders, and also learn and improve their performance, e.g. by altering their preferences. It seems that biological evolution 'discovered' the importance of virtual machines long before we did and produced far more sophisticated self-monitoring and self-modifying virtual machines than any we have created so far. The empirical work of Beauregard and Schwartz (among others) helps to shed light on some of the detailed ways the biological virtual machines operate. The intractable puzzles of philosophers show some of the limitations of those biological virtual machines. Unfortunately most philosophers (and also psychologists and neuroscientists) who discuss mind-brain relations, supervenience and implementation (unlike Dennett and Clark) are largely ignorant of the existence and capabilities of virtual machines in computers and completely ignore them when discussing and writing about mind-brain relations, even though they use several interacting virtual machines on their computers, while writing their papers, checking and sending email, looking up references using web browsers, etc. To help people who want to understand, I have recently produced an online tutorial on 'Virtual Machines in Philosophy, Engineering and Biology', expanding some of these points, based on a recent conference presentation, here: http://www.slideshare.net/asloman/slideshows It is also available here: http://www.cs.bham.ac.uk/research/projects/cogaff/talks/#wpe08 Yours Aaron Sloman Honorary Professor of Artificial Intelligence and Cognitive Science University of Birmingham http://www.cs.bham.ac.uk/~axs/ http://www.cs.bham.ac.uk/research/projects/cogaff/talks/
School of Computer Science
The University of Birmingham