John F. Sowa wrote:
>> First-order logic is therefore only for the top 20% of data modelers,
>> not the average...
> I suspect that Ian and Ed are mistakenly equating FOL with a concrete
> notation like predicate calculus or CLIF. I keep telling people that
> they've been speaking FOL all their lives. Every sentence that
> the words 'and', 'or', 'not', 'if', 'some', or 'every' is using full
> FOL or some subset of it.
I think, John, that you are here exemplifiying the top 20%, who think
that every other competent engineer can do more or less what they do.
My experience has been quite the opposite. All these professionals
understand logic in a casual, intuitive way. Many people use modeling
languages in the same way, to state unclear thoughts clearly and often
incorrectly. They don't use the language to mean exactly what the
formal semantics of the language says is meant by the syntax they used.
Many people have no problem with simple syllogisms, but are seriously
confused about quantification.
A very intelligent engineer I recently worked with could not tell the
Bank Manager: a person who manages a bank
Manager: the person who manages a given bank.
The first is a relation -- a classifier; it contains an existential
quantification of bank. The second is a function -- it maps banks to
persons. We know that; but he merged the concepts, by using the first
definition to mean both, not realizing that the English phraseology is
And I can tell you first hand that the first encounter between
electrical engineering students and boolean algebra is a filter -- the
ones who will work in electronics understand quickly, the ones who don't
understand quickly will become radar technicians or something. It is
not just the notation; it is the abstraction. Many of the
simplifications of gating logic are counter-intuitive.
FOL is not casual logic; it is a mathematical discipline. Many
intelligent people can use logic correctly in their work, but they don't
the discipline, and most of them don't understand that there is a
discipline. Logic for them is fine until it contradicts their
intuition, and then they discount it, and they will argue erroneously
against it. Everybody can use if, and, and or correctly some of the
time. The discipline is in using them correctly _all_ of the time.
Conversely, the most astonishing use of FOL I have ever seen was a
3-year-old, who was looking out the office window of a colleague at a
blossoming cherry tree. She said to him, "you have to be up here to see
that tree. I guess you've never been up on the 3rd floor before." And
he replied, "No. Well, I don't think so. But my Dad's office is on the
3rd floor, and I was in my Dad's office. So I must have been on the 3rd
floor." !!! Modus ponens at age 3, in contradiction of intuition!
average engineer. :-)
Edward J. Barkmeyer Email: edbark@xxxxxxxx
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
Gaithersburg, MD 20899-8263 FAX: +1 301-975-4694
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority."
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