The greatest challenge of doing philosophy today may be one of not being able to see the forest for the trees. Whether teachers and students will readily admit to it, the content of philosophical studies is too often presented in twigs, many of which are rarely if ever connected to larger branches of thought. The problem for students is not usually one of understanding a particular argument, but rather understanding where and how all the arguments fit together.
Consider, for example, the difficulty involved in trying to determine the current status of a longstanding philosophical debate. What arguments have already been made? Which have been rebutted? Who has argued what against whom? What counter-rebuttals have been offered? The most interesting and important arguments are usually carried on in the journals of several different fields. Research and the debates over the nature of consciousness, for instance, appear in the journals of neurobiology, cognitive science, anthropology, psychology, and philosophy. How can we expect to keep track of what is being currently thought about or written on the subject?
At the same time, philosophers and students of philosophy also have wide-ranging curiosity. Most of us still want to know what's happening outside of the narrow speciality that occupies so much of our professional life. Yet we live in an age of information overload. To continue the botanical metaphor, we are too often lost in a dense wood of interesting but unconnected thought on important topics. The sheer number of good journals continues to rise, making it impossible to scan, let alone read, all of the articles that might interest us. How can we expect to navigate, let alone benefit, from such abundance?
How argumentation
maps came about
About 12 years ago I asked myself the question: What is the status
of the great philosophical debates that have preoccupied humanity
over the centuries? I realized almost immediately there was no
easy answer. After considering the question for a while, I had
to admit that I didn't have a good picture in mind about how the
status would even be displayed. It was apparent that this was
a worthy project to work on. I had some exposure to an emerging
profession, information design (Horn, 1998b), which is concerned
with exactly the issues of presentation of complex information
to make it efficiently and effectively available to a wide group
of people. The possibility that some form of diagramming might
facilitate display of the status of a debate was the beginning
of the project.
Stephen Toulmin's pioneering work, literally creating the new field of argumentation analysis (1958), offered me a framework. Toulmin had suggested that we look to how people in various professions actually argue and attempt to sort their arguments into their components (claims, grounds, backing, warrants, rebuttals). His framework provided a way to begin my early experiments. I tried that approach early on in the project and found that, graphically, it produced a page that strongly resembled a plate of spaghetti. It was too confusing and overwhelming to the reader and the analysis was too fine-grained to provide the overview of the arguments I was looking for. After many failures, I worked out a diagrammatic scheme that clustered these Toulmin-elements into a single box connected by arrows that showed the basic relationship of "supports" or "disputes" of a particular claim (or claim plus supporting arguments). This provided both the simplicity and the structure I was after. It became clear that what I was trying to do was to create a kind of map of the great debates.
In the early 90s I began gathering a team of students and colleagues to attempt to map one of the great debates. We wanted a debate that was currently being argued, one that was neither too extensive for our resources, nor too tiny to provide a robust test of our developing methodology. Others had used Toulmin-like diagramming, but we wanted to test it on an important, sizable, real-world debate. As we completed the different topics, they were shown to experts in the relevant issues for feedback.
Can Computers Think?
The Debate
We settled on the Turing debate about whether computers can think
(or if they ever will be able to think). The debate starts with
the 1950 claim of the great British mathematician, Alan Turing.
He wrote, "I believe that at the end of the century the use
of words and general educated opinion will have altered so much
that one will be able to speak of machines thinking without expecting
to be contradicted." In short, he was certain that computers
would be able to think. That was a powerful claim especially coming
from the mathematician who in the 1930s invented the ideas on
which the modern computer is based. For our purposes, this debate
had a pretty clear beginning (although philosophers as far back
as Descartes and Leibnitz had speculated on the question). It
had attracted some of the best minds of our century. There was
a wide range of kinds of arguments and an interesting interdisciplinary
nature to the debate that would surely confront our budding methodology
with interesting and useful problems. It touched on so many of
the ongoing topics in philosophy, especially in the philosophy
of mind and consciousness. The artificial intelligence debate
also focused deeply on the philosophy of mathematics and on the
philosophy of science. Moreover, it also incorporated some issues
in neurobiology and opened up deeper questions as to the nature
of computation and the nature of machines and persons. Yet, for
the most part the debate was not too technical, and hence quite
accessible to most.
The Can Computers Think? debate provided us multiple entry points into major areas areas of philosophy. In his paper launching the debate, Turing himself delved into many of these topics. He touched on such subjects as machine creativity, free will, and emotions. Turing asked: what is the status of God if machines can think? And, of course, with the development of the Turing Test he deeply focused our attention on the nature of thinking. All of these are topics that students can and should wonder about.
The Turing debate has engaged literally thousands of scholars, philosophers, cognitive scientists, mathematicians, physicists, neurobiologists and researchers from other fields. And has engaged some of the best minds of all time: along with Turing, mathematicians Godel and von Neuman; the pioneer cognitive scientists Philip Johnson-Laird, Alan Newell and Herbert Simon; the inventors of artificial intelligence as a field, John McCarthy and Marvin Minsky; the physicist Roger Penrose; and, of course, philosophers from Leibnitz and Descartes to the contemporaries Hubert Dreyfus, John Searle, Daniel Dennet, Douglas Hofstadter, Paul and Patricia Churchland, and many others. Surely, this debate is at the forefront of questions of the philosophy of mind and surely it could adequately challenge our methodology.
The structure of
the maps
The main structure of our maps is that of a large tree with many
branches. (See Fig. 1) The tree begins with Turing's claim, quoted
above. The structure is then quite simple. It proceeds by laying
out the branches of claim, rebuttal, and counterrebuttal. One
of our criteria for mapping the debates was that if there was
no debate, the claim did not make it on to the charts. Such agreements
are most often found in the sidebars on our maps.
Figure 1

Links
The major links in the maps' branches are labeled arrows, the
arrows being identified by icons that bear the words "is
disputed by" or "is supported by." The reader follows
a branch, noting whether it is supporting or disputing the claim
in the previous box, and then reads the next claim or rebuttal.
Each thread of argument serves as a timeline of the argument,
left to right, thus providing one of the innovations of these
maps, a visual intellectual history of the debate. (See Fig. 2)
Claims
Each claim box identifies the protagonist and the year and contains
the summary of the claim, support, or rebuttal. (See Fig. 2) A
major aim of the writing is to summarize the claim in as clear,
simple, and direct a manner as possible.

Focus boxes
Each of the 70 major branches or issue areas of the debates are
labeled with a question and begin with a focus box that summarizes
the general claim of that issue, which we call a "focus claim."
These claims can sometimes be attributed to a specific protagonist
in the argument. But just as often other protagonists argue against
this focus claim, even though they do not cite anyone who has
actually claimed it. And, in fact, we have been unable at times
to find anyone, in print, who has specifically claimed what the
claim box summarized. Rather, authors will write "there are
those who argue," or "it is sometimes claimed..."
Secondary Links
Occasionally notes within the boxes provide secondary links which
help readers tie together important connections.
Understanding the
camps
One of the difficult aspects of understanding great debates like
this one, is that the protagonists come from quite different points
of view. They bring vastly different assumptions about the nature
of reality. Often, in a specific article students must read, the
protagonists do not reveal their assumptions or their affiliation
with a specific camp of thinkers. We have tried to provide a tool
for learners here also. The basic clue was provided by Simon and
Newell's listing of their postulates for the representationist
point of view, which they call the physical symbol system hypothesis.
We then wrote sets of postulates for nine other major points of
view and have included them on the various maps. We identified,
where possible, which participants on the maps could be regarded
as being part of a specific camp, thereby providing students with
an insight as to why particular arguments might be taking place.
Sidebars
To aid immediate comprehension of some of the topics on the maps,
we included 50 definitions and 32 sidebars. These are located
at strategic spots in the maps close to where the topics and terms
are introduced.
The uses of argumentation
maps in teaching
Philosophical argument is a lively, current concern. We took our
inspiration from the biologist Lewis Thomas, who wrote, "College
students, and for that matter high school students, should be
exposed very early, perhaps at the outset, to the big arguments
currently going on among scientists. Big arguments stimulate their
interest, and with luck engage their absorbed attention... But
the young students are told very little about the major disagreements
of the day; they may be taught something about the arguments between
Darwinians and their opponents a century ago, but they do not
realize that similar disputes about other matters, many of them
touching profound issues for our understanding of nature, are
still going on, and, indeed are an essential feature of the scientific
process."
Some possible learning assignments
The maps lend themselves to assignments that involve students
in the debates immediately. For example, an early assignment in
a course could be: Choose one of the 70 major branches of the
debate, decide whether you agree or disagree, and write a paper
giving your reasons. A moderately more difficult assignment would
be to ask students to rank order the strength of different debates
on a given branch and consider why they give the weights they
do to the different arguments. A more advanced assignment could
ask students to come up with at least one new argument at the
end of one of the branches, which represent the frontiers of the
debate. An even more advanced assignment could be to ask students
to write a paper that shows why two or more of the eleven philosophical
camps described in postulates on the maps are debating a particular
issue.
Excellent hook for student interest in introductory courses
Students often find that it is easier to get into a subject that
has some connection to currently hot topics in the culture. The
maps can be used to introduce questions of philosophy in a way
that is attractive and compelling. Many students will have heard
of the IBM computer system, Deep Blue, that recently beat Garry
Kasparov, the human Grandmaster champion, at chess. They may have
seen it on the TV news or on the covers of weekly newsmagazines.
These events make it possible to pose such questions as: Can Deep
Blue really think? What kinds of thinking is Deep Blue doing?
The chess-playing arguments appear on Map 3 of this series. As
I have suggested above, the question about computer thinking opens
more doors to more other philosophical issues than any other topic.
For this reason alone it lends itself to introductory survey courses
aimed at intriguing students with the study of philosophy.
Learning philosophy dialectically
By watching philosophers lock horns and wrestle in an interdisciplinary
arena of open debate, readers can better appreciate the subtlety
and complexity of the issues with which they themselves are struggling.
The dialectical method has ancient roots and remains valuable
today. Socrates grappled with the best minds of Athens in public
debate, and Plato recorded those dialogues as a means of teaching
philosophical concepts. Argumentation maps illustrate the value
of learning philosophy dialectically. Argumentation maps graphically
harness the full communicative and instructional power of dialectical
exchange.
Provide project opportunities in creative argumentation
Rarely do students get a chance to feel that they are participating
in what is happening today. It is difficult to convey a sense
of the leading edge of arguments. To see where debates have stopped
or slowed down, students only have to read along the right-hand
edge of an issue area. Because the argumentation maps provide
the thread of existing arguments, and also show where they have
ended (as of now), they provide the opportunity for assigning
students to select one thread or topic of an argument and try
to add to it an original argument, write a critical essay about
it, or read the original sources of one or more issue areas and
critique them. Since the maps clearly mark the frontiers of arguments,
students have a chance to engage in real debates and contribute
their critical assessments as well as new arguments. This, in
itself, has suggested to teachers an extraordinary educational
opportunity.
Save time and provide context and visible structure
We live in an age of information overload and specialization.
The sheer numbers of argumentative moves (over 800); the number
of authors represented on the maps (380); the number of sources
that we consulted (over 1,000) and the sources that contained
original arguments used in the maps (over 400) are overwhelming
to the student undertaking study in this area. One graduate student
in the philosophy of
mind said: "These maps would have saved me 500 hours of time
my first year in graduate school. For almost two semesters, I
had to keep reading article after article without enough context
to see how they fit in to the bigger picture. The maps would have
made my whole experience a much more rewarding one." It was
also interesting to hear from a professor of philosophy of mind
who had begun using the maps in her teaching. She reported that
"The maps have, in fact, prompted me to reorganize my Philosophy
of Mind course to cover certain issues and problems from a particular
approach, using the commentaries of thinkers noted on the maps--e.g.
the Chinese Room in more depth, and connected more explicitly
to the question 'Can Computers Think?'" (Wagner, 1998)
Can other topics
be mapped?
A number of philosophers have remarked on the general usefulness
of our methodology and have asked us if other topics are underway.
The short answer is yes. We are proceeding on maps of several
other major debates, in the interdisciplinary study of consciousness
(by neurobiologists, psychologists, and philosophers), in some
topics in the philosophy of biology (especially in evolution),
in ethics, and have proposals out for still others, especially
in political philosophy and public policy issues. We believe that
this mapping approach will serve education by providing a general
methodological tool and by providing authoritative maps in substantive
areas.
More opportunities
The educational opportunities I itemized are only the beginning,
because these maps are literally only a beginning. To use a cartographic
metaphor, the maps are at the stage that Mercator's projections
were in the creation of mapping methods. Since then literally
hundreds of new and different kinds of projections have been devised.
Even more sophisticated uses than Mercator ever dreamed of have
been made of the mapping approaches that he originated. I am sure
that other scholars will come up with creative new maps and extraordinary
new educational uses for them that we on the project have not
yet thought of. We are interested in feedback from the field as
to other topics that might be addressed.
What's the answer?
Can computers think?
Our philosophy in creating the maps was not to evaluate the weight
of the arguments summarized. Our goal as mapmakers was to map
the debate without taking a personal stand. The maps are, as much
as possible, neutral.
This highlights another aspect of our philosophy in making the maps. They are intended as educational tools to help students learn to think critically. It is left to students to evaluate the "weight" of the arguments and evidence and draw their own conclusions. Some students have been frustrated by this. They say, "So, what's the answer?" The maps do not provide the answer. This provides instructors with many more educational options and opportunities and students with the chance to evaluate the arguments and make up their own minds. It is not intended that our maps reveal the mapmakers' views.
Of course, the maps are to some extent interpretive. In writing and linking arguments, we had to condense huge amounts of information, often on the basis of highly obscure or technical literature. We also had to make decisions about placement and emphasis. The way these maps organize the debate is not necessarily the only possible organization, but it was carefully considered and weighed against alternatives. The argument summaries themselves, which is where the real dialogue takes place, stick closely to the words of the authors, the better to avoid interpretation.
Conclusions
Karl Popper, the 20th century philosopher of science, has said,
"The best tested theory is the one which, in the light of
our critical discussion, appears to be the best so far;
and I do not know of anything more 'rational' than a well-conducted
critical discussion." Argumentation maps provide a picture,
more detailed than previously available, of how such a vast critical
discussion can take place across disciplinary and geographic distances.
By creating an accessible map of the conceptual territory our
hope is to facilitate more global interdisciplinary debate, to
bring the various sources to light, and to illuminate how the
pieces of the puzzle fit together. Perhaps the very existence
of the maps will provide incentive and opportunity for more interdisciplinary
and international discussion. It is all too easy to repeat an
argument that has already been made in a distant or obscure location,
to talk past one another in the heat of conflict, or to ignore
important context. It is all to easy in the age of information
overload for even the most careful scholar to not
know that a major rebuttal has already been made. Moving a serious
debate forward requires a disciplined interdisciplinary and international
dialectic and the right kind of tools.
Acknowledgements
I want to salute the members of my team, Jeff Yoshimi, Mark Deering,
(of the University of California, Irvine) and Russ McBride (University
of California, Berkeley), without whose dedicated effort and creative
thought these maps would not be what they are today. I also want
to thank the publishers, MacroVU, Inc. and the Lexington Institute
for their generous support of this project.
Notes
(1) The field of argumentation analysis has several associations,
including the International Society for the Study of Argumentation.
References
Horn, R. E. (1998a) Mapping Great Debates: Can Computers Think?
A series of seven maps and Handbook. MacroVU, Inc. Bainbridge
Island, WA. (Examples are provided on the publisher's website
<www.macrovu.com>
Horn, R. E. (1998b) Visual Language: Global Communication for the 21st Century. MacroVU, Inc. Bainbridge Island, WA.
Thomas, L. (1981). Debating the Unknowable. Atlantic Monthly, July, 49-50.
Toulmin, S. (1958). The Uses of Argument, Cambridge: Cambridge University Press.
Turing, A. (1950). Computing machinery and intelligence. Mind 59, 434-460.
Wagner, E. (1998) Personal communication. Full text available at http://www.macrovu.com