Re: Babbage/Menabrea: Analytical Engine

From: HARNAD Stevan (
Date: Mon Mar 19 2001 - 11:55:42 GMT

On Wed, 28 Feb 2001 wrote:

> Button:
> [Menabrea/Babbage] perceives the
> possible two domains of mathematics as mechanical and intellectual - in
> particular understanding. He then goes on to suggest that due to the
> laws evident in the 'mechanical' domain, it would be possible to employ
> machinery to execute mechanical calculations, and therefore ease the
> workings of such problems.

So you see, today's question is already raised from the outset: Could
the intellectual/understanding part (intelligence) itself be
mechanical (computational) too? Or is computation merely an aid to the

> Button:
> problems that could be solved by such machines were limited to the
> 'mechanical' domain anyway, so essentially it was not a drawback.

Unless there are things the mind can do that are not "mechanical"
(i.e., computational)...

> > There are certain functions which necessarily change in
> > nature when they pass through zero or infinity, or whose values
> > cannot be admitted when they pass these limits. When such cases
> > present themselves, the machine is able, by means of a bell, to give
> > notice that the passage through zero or infinity is taking place, and
> > it then stops until the attendant has again set it in action for
> > whatever process it may next be desired that it shall perform.
> Button:
> Such a condition of the engine suggests a certain amount of useful
> 'intelligence'. That is that it does not just blindly follow it's
> instructions to calculate results from given data and operations, but
> can also alert the operator if a problem is going to arise. However,
> this is simply a reaction to particular data and cannot really be
> considered as 'thought' even though fulfilling such a task allows the
> resulting data to be error-free.

Don't you have it a little backwards here? Ringing a bell when there is
a zero-crossing is surely no more (or less) "intelligent" than computing
itself! And surely asking for the help of an intelligent being is
cheating, rather than a sign of intelligence...

> > Considered under the most general point of view, the essential object
> > of the machine being to calculate, according to the laws dictated to
> > it, the values of numerical coefficients which it is then to
> > distribute appropriately on the columns which represent the variables,
> > it follows that the interpretation of formulae and of results is
> > beyond its province, unless indeed this very interpretation be itself
> > susceptible of expression by means of the symbols which the machine
> > employs. Thus, although it is not itself the being that reflects, it
> > may yet be considered as the being which executes the conceptions of
> > intelligence
> Button:
> By this Menabrea suggests that the engine itself is not intelligent,
> instead it aids intelligence.

But what does that mean about the nature of intelligence itself? Does it
mean that what is going on in the head of the intelligent being cannot
be just computation too?

Could the "interpretation" problem be the symbol grounding problem?
> As considered in the early parts of the paper, the purpose of such
> machines as Babbage's and also the attempt of Pascal, was to aid in
> computation. That is to execute whole calculations, or ease
> calculations such that the scientist or mathematician could spend
> his/her time on the intellectual contemplation of more 'serious'
> matters. In this way, the concept of Babbage's Analytic Engine
> fulfilled it's purpose, and although it itself could not interpret the
> data produced, it could allow the operator to forgo the time consuming
> task of calculation.
> Although this can be interpreted to be unintelligent due to the simple
> following of set rules, if this were the case of a considered
> 'intelligent' system (human for example), the following of such an
> algorithm would be taken to be intelligent - not necessarily highly
> intelligent (whatever that means) - but surely intelligent nonetheless.

I couldn't follow this. If the computation, in Babbage's case, was the
mechanical, unintelligent part, which the intelligent being was relieved
of having to do, by the aid of the engine, then what would it take to
make the engine intelligent (forward engineering)? And what is going on
in the head of the intelligent being (reverse engineering) if it is not
just computation?

Stevan Harnad

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