School of Computer Science THE UNIVERSITY OF BIRMINGHAM CoSy project
From Aaron Sloman Tue Jan 23 23:29:16 GMT 2007

Dear organisers.

Although I'll not be at the symposium, I am responding to the
announcement inviting tributes, stories, and well wishes for John
McCarthy's 80th birthday. Since nothing was said about format, I am
writing it in plain text. But if you'd prefer latex or html or pdf I can
convert it. I never use Word, and don't like OpenOffice, but can
tolerate it, if you want odt format.

Best wishes.
Dear John,

I am very sorry I won't be at this symposium, especially as I have
learnt so much from your writings since I first encountered AI around
1969, and in a sense I owe my first ever AI publication to you (and Pat
Hayes). I had been reading some of your papers presenting the logicist
approach to AI and when I read this paper

    J. McCarthy, P.J. Hayes, 1969,
    Some philosophical problems from the standpoint of AI,
    Machine Intelligence 4, Eds. B. Meltzer and D. Michie,
    Edinburgh University Press,

its strong claims provoked me into writing a paper presented at IJCAI
1971, subsequently reprinted in the AI Journal and a couple of other

I argued that despite the power and usefulness of logic (and more
generally Fregean representations, built on the function/argument
structure) that was not sufficient for the purposes of an intelligent
system; and suggested that other forms of representation were needed,
including (among other things) what I called 'analogical'
representations (in which properties of and relations between parts
represent properties of and relations between things represented, though
they need not be isomorphic with what they represent, since e.g. a 2-D
picture can represent a 3-D object despite being far from isomorphic
with it). I also argued that the notion of a 'valid inference' had to be
extended to include inferences represented by manipulations of spatial

We first started talking at that conference, though I can't recall what
you said then! Later you kindly invited me to spend a month in Stanford
during 1981, the year in which you had Sloan foundation funds to bring
philosophers and AI researchers together. Thereafter, I met you from
time to time at conferences and during visits to Stanford, always
finding our conversations interesting and rewarding. I've also continued
to learn much from your writings (even when I did not agree with

In particular I urge people to look at an unpublished paper on your

    'The well designed child',

It should especially be read by all those AI researchers working on
learning, who need to be reminded that

    "Evolution solved a different problem than that of starting a baby
    with no a priori assumptions."


    "the world is not structured in terms of human input-output

    "Animal behavior, including human intelligence, evolved to survive
    and succeed in this complex, partially observable and very slightly
    controllable world. The main features of this world have existed
    for several billion years and should not have to be learned anew
    by each person or animal."


Let's hope the next 50 years of AI research will be more strongly
influenced than the last 50 years by that viewpoint, and the implication
that in order to design human-like robots we need a deep understanding
of the structure of the world that shaped our evolution, including
the evolution of our potential to use logic!

Best wishes.
Aaron Sloman
School of Computer Science
The University of Birmingham, UK

Maintained by Aaron Sloman
School of Computer Science
The University of Birmingham
Updated: 28 Oct 2008