SEMIOTICS, MODELS AND COMPUTING
Bertil Ekdahl
Department of Computer Science, Lund University
Ole Römers väg 3, SE-223 63 Lund, Sweden
Keywords: Computational semiotics, formal system, language, models, semiotics.
Abstract: Recently, semiotics has begun to be related to computing. Since semiotics is about the interpretation of
signs, of which language is a chief part, such an interest may seem quite reasonable. The semiotic approach
is supposed to bring semantics to the computer.
In this paper I discuss the realistic in this from the point of view of computers as linguistic systems, that is,
as interpreters of descriptions (programs). I maintain the holistic view of language in which the parts are a
whole and cannot be detached. This has the implication that computers cannot be semiotic systems since the
necessary interpretation part cannot be made part of the program. From outside, a computer program can
very well be considered semiotically since the equivalence between computers and formal system implies
that there is a well defined model (interpretation) that has to be communicated.
1 INTRODUCTION
Semiotics is a branch that recently has been of
interest for computer scientists in development of
information system. Shortly, semiotics can be
characterized as the “study of signs and their
meanings”. With sign is not only meant written signs
but also signs in artistic disciplines like music and
theatre. On the whole, semiotics is about the act of
interpretation. As is clear, language is a chief part of
it.
The interest in semiotics in computer science
stems from the idea of seeing computers as sign
systems. Andersen (Web, p.5) writes:
“A computer system can be seen as a complex
network of signs, and every level contains
aspects that can be treated semiotically.”
Andersen further believes that semiotics is a
global perspective on computer systems. He points
to the different views in which computers can be
treated; on the one hand one can focus on the
mechanical aspect, in which case “semiotics has
little to offer”, on the other hand on the
interpretational aspect, which latter is the semiotic
approach. Andersen seems here to consider a
computer system as a black box whose properties it
is the aim to reveal and it is in this process semiotics
comes in.
Another view of computational semiotics is the
idea that a computer in itself can be a semiotic
system involving its own understanding. This view
is put forth not at least by Gudwin [Web]:
“Computational Semiotics refers to the attempt
of emulating the semiosis cycle within a digital
computer. Among other things, this is done
aiming for the construction of autonomous
intelligent systems able to perform intelligent
behavior, what includes perception, world
modeling, value judgment and behavior
generation. […] Within Computational
Semiotics, we try to depict the basic elements
composing an intelligent system, in terms of its
semiotic understanding.”
As Andersen points out, thinking of computers as
physical machines does not relate computers to an
interpretative view but seeing a computer as an
interpreter of a program, (sentences) makes it a
linguistic system, qualitatively connected to our own
linguistic cerebral system, the foundational aspects
of which is logic.
A linguistic system has both a description
(sentences) and an interpretation of the description.
Were it possible for a computer to be a semiotic
system, as Gudwin assumes, it would, by itself, be
able to describe its own interpretation. However, this
is not possible due to a complementarity in
283
Ekdahl B. (2008).
SEMIOTICS, MODELS AND COMPUTING.
In Proceedings of the Tenth International Conference on Enterprise Information Systems - ISAS, pages 283-289
DOI: 10.5220/0001702602830289
Copyright
c
SciTePress
language. The domain of the validity of a description
is of a higher type than the description itself. In that
sense a computer will never be a semiotic system but
semiotics could be of value for studying computers
as linguistic systems. Such a study needs a
metalanguage for which purpose semiotics may
serve.
2 SEMIOTICS
Its origin can be traced back to the Swiss
philosopher Ferdinand de Saussure and the USA
philosopher Charles Saunders Peirce. Saussure
(1966) explained semiotics as “the science of the life
of signs within society”. (Saussure, 1983):
“It is... possible to conceive of a science which
studies the role of signs as part of social life. It
would form part of social psychology, and hence
of general psychology. We shall call it
semiology (from the Greek semeîon, 'sign'). It
would investigate the nature of signs and the
laws governing them. Since it does not yet exist,
one cannot say for certain that it will exist. But
it has a right to exist, a place ready for it in
advance. Linguistics is only one branch of this
general science. The laws which semiology will
discover will be laws applicable in linguistics,
and linguistics will thus be assigned to a clearly
defined place in the field of human knowledge.”
Peirce [1992] makes the following explanation of
what he called semiosis:
“[B]y ‘semiosis’ I mean […] an action, or
influence, which is, or involves, a cooperation of
three subjects, such as a sign, its object, and its
interpretatant, this tri-relative influence not
being in any way resolvable into actions
between pairs. “
From his understanding of Peirce, Morris
proposed that semiotics embraces syntax, the
morphology, semantics, what the words and signs
stand for, and pragmatism, the relation of signs to
the interpreter.
Syntax and semantics are well known parts while
the third part, pragmatism, is what Bar-Hillel (1970)
characterized as the “waste-basket”, i.e., a place to
put everything that is “difficult”. Sonesson (2002) is
concerned about the absence of explanatory power
of pragmatism:
“[…]’pragmatic’ approaches often leaves as a
complete mystery how meaning is conveyed”.
Computational semiotics is thought of as a way
“to synthesize artificial systems able to perform
some sort of semiosis” (Gomes et al., Web). They
further submit that according to Peirce, any
description of semiosis involves a relation of three
terms:
“A sign is anything which is related to a Second
thing, its Object, in respect to a Quality, in such
a way as to bring a Third thing, its Interpretant,
into relation to the same Object, and that in such
a way as to bring a Fourth into relation to that
Object in the same form, ad infinitum.”
In order to simulate, as they said, semiotic
systems, they try to devise a suitable formalism. As
will be shown, a new formalism is still a formalism
and will not make a system semiotic in itself.
Andersen, on his part, discusses three different
kinds of semiotic and linguistic theories: the
generative paradigm, the logical paradigm and the
European structuralist paradigm of which he reject
the two first. However, Andersen cannot reject the
logical paradigm since a computer, as a linguistic
system, is a logical system and cannot be differently
considered.
3 FORMAL SYSTEM
Formal system (logic) “is concerned with the
analysis of sentences or of propositions and of proof
with attention to the form in abstraction from the
matter.” (Church, 1956, p. 1)
This total abstraction from meaning is expressed
by Kleene (1952, p. 61) as follows:
“To Hilbert is due now, first, the emphasis that
strict formalization of a theory involves the total
abstraction from meaning, the result being
called a formal system […]”
Thus, the whole idea with a formal system is to
serve as a proof system; a system whose only aim is
to produce proofs. In accomplishing this, everything
except form must be rejected. It is like a play with
pieces that does not in itself have meaning. von
Neumann (1931) explicates the game idea in the
following sense:
“[C]lassical mathematics involves an internally
closed procedure which operates according to
fixed rules known to all mathematicians and
which consists basically in constructing
successively certain combinations of primitive
symbols which are considered “correct” or
“proved”. […] [W]e should investigate, not
ICEIS 2008 - International Conference on Enterprise Information Systems
284
statements, but methods of proof. We must
regard classical mathematics as a combinatorial
game played with the primitive symbols.”
(italics, BE)
Hence, a formal system is constructed to be free of
semantics.
The first step in setting up a formal system
(logical system) is to list the formal symbols. Here,
any symbol will do; no one is preferable for the
system but possibly for the user of the system. For
example, in a formal system for arithmetic we can
choose the symbol Ŋ to stand for the number one.
However, it is normally better to use the symbol
1
because it immediately gives the user the intended
interpretation.
From the symbols the formal expressions are
derived. The next step is to introduce the formation
rules which can be considered as analogous to the
rules of syntax in grammar. The third step is to
define transformation rules. The transformation
rules, or inference rules, give the formal system the
structure of a deductive system or deductive theory.
What is stated above is the same for all formal
systems. What distinguish different formal systems
are the postulates (axioms) that turn a formal system
into a theory. For example, for number theory the
following are two postulates:
))(0(
)()(
xSx
yxySxS
=¬∃
==
where S is interpreted as the successor function, with
the meaning that S(x) is the next number coming
after the number symbolized by
x. The first sentence
is then interpreted as “if the successors of two
numbers are the same, the numbers are the same”.
The second axiom says that “zero is the least
number”. As will be seen, there are other possible
interpretations.
The relation of formal system to computers
1
is
clearly expressed by Gödel (1964) in a postscriptum,
prepared to Martin Davis:
“In consequence of later advances […] due to
A. M. Turing’s work, a precise and
unquestionably adequate definition of the
general concept of formal system can now be
given [,…] A formal system can simply be
defined to be any mechanical procedure for
producing formulas, called provable formulas.
For any formal system in this sense there exists
1
In this paper I will not distinguish between formal
system, computer and Turing machine.
one in the sense of page 41 above
2
that has the
same provable formulas (and likewise vice
versa), provided the term “finite procedure”
occurring on page 41 is understood to mean
“mechanical procedure”. This meaning,
however, is required by the concept of formal
system, whose essence it is that reasoning is
completely replaced by mechanical operations
on formulas.”
A formal system, used to develop formal
theories, is a system that utilizes processes, which
cannot themselves be completely described by some
theory in the system in question.
4 THE USE OF MODEL IN
NATURAL SCIENCES
There is no doubt that the term model is used in
many different ways, not only in everyday life but
also in science. Frequently the term is used in a
manner that makes its meaning diffuse, and also
there is a common tendency to confuse, or to
amalgamate, the terms model and theory. Even in
science those terms are often used interchangeably
as being synonymous.
Andersen (Web) argues that semiotics and
natural science are different in perspective. The
reason he states is that “natural science focuses on
the mechanical aspects of a system – those aspects
that can be treated as an automaton – semiotics
focuses of the interpretative aspects”. For Andersen
it seems as computer systems are sign systems
whose interpretations have to be wormed out.
However, there is a huge difference between a
computer system and a natural system. When
studying physics the system is unknown and starts
with observations with the aim to reveal a physical
structure. That is, we try to get an idea of the nature.
With computer systems it is the other way around.
Like all other artificial systems, the interpretation
(idea) is already known; it is the starting point. No
surprises are to be expected. For example, no one
constructs a gear box and then ask for its behavior.
We characterize the nature in such a way that it
can be grasped and, hopefully, visualized. This
visualization is a model like a model ship or model
plane. It is not the equations, the theory, that
constitutes a model. For example, in the 1920s and
1930s, the Friedman-Robertson-Walker
cosmological model was introduced as the simplest
2
Refers to p. 41 in Davis, 1965.
SEMIOTICS, MODELS AND COMPUTING
285
solution of the equations of Einstein’s general theory
of relativity. This cosmological model was a way of
thinking of the Universe in a way that satisfied our
understanding of the Universe while at the same
time keeping Einstein’s equations. This model was
non-rotating. However, Gödel was the first to
consider a model that was rotating. The curious
property of this model was that in it, it was possible
to travel into the past. The equations, that is, the
theory, were not altered but the interpretation was
quite new and much unexpected.
The interpretation aspect is everywhere present
in natural sciences. For example, Niels Bohr
struggled all his life with the question of the
interpretation of quantum theory and still today there
is no good interpretation of quantum phenomena.
Penrose has explained the difficulties as follows:
(Web)
“It must play its role when magnifying
something from a quantum level to a classical
level, which is what is involved in measurement.
The way to treat this, in standard quantum
theory, is to introduce randomness. Since
randomness comes in, quantum theory is called
a probabilistic theory. But randomness only
comes in when we go from the quantum to the
classical level. If we stay down at the quantum
level, there is no randomness. It is only when we
magnify something up, and make a
measurement. This consists of taking a small-
scale quantum effect and magnifying it out to a
level where we can see it. It is only in that
process of magnification that probabilities come
in.”
What Bohr wanted and Penrose wants is to find a
model of the quantum phenomena.
The confusing usage between model and theory
is harmless so long as we stay intradisciplinary but
when it comes to the explanation of systems that we
think of as having a cognitive ability, and
particularly systems which are furnished with
language, it is of importance to use the term model
in its linguistic sense otherwise it is easy to ascribe
properties to such systems that they never will
achieve.
5 MODELS IN LOGIC
Formal systems have “mathematical models” which
is a well defined concept. It is of no use to construct
a formal system without giving it a definite model,
i.e., giving the key of interpretation.
A model of a formal system is a (mathematical)
structure that consists of a non-empty set, called
domain, a set of functions, a set of relations and a set
of constants. In mathematical notation it is described
as
kmn
cccRRRfffA ,...,,,...,,,,...,,,
212121
where A is the domain, the fs are functions, the Rs
are relations and the cs are constants.
As an example we may consider a graph. A
graph is a set V (of vertices) and a set E (of edges),
where each edge is a set of two distinct vertices. An
edge {v,w} is said to join the two vertices v and w.
For example, a subway system constitutes a graph in
the sense above where the stations are the nodes and
the connections between the stations are the edges.
There is a natural way to make a graph V into a
structure G. The elements of G are the vertices.
There is one binary relation R. The ordered pair
wv, lies in R if and only if there is an edge
joining v to w.
Now, every natural structure, that can be
described in detail, can be turned into a
mathematical structure and if then a sentence is true
in the mathematical structure it is also true in the
natural structure and we may call the natural
structure a model of the sentence.
By way of example (fig. 5.1), we may consider a
sphere falling from a tower. This is the natural
(physical) model which can be turned into a function
which constitutes the mathematical model. The
program then is the theory of the model but does not
in itself say anything of what is computed.
Figure 5.1: The equation for a freely falling sphere.
A program can have many different models and
no one is pointed out by the program. For example,
the first sentence, in the postulates mentioned above
for arithmetic, can be given the interpretation that “if
two people have the same security number, then it is
one and the same person”. Another interpretation
could be the DNA-sequence of a person. Then the
axiom could state that “if a murder and a decent
ghv 2=
Program
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286
person have the same DNA, then the decent person
is the murder”. In this interpretation the second
axiom could be thought of as meaning that “there is
no person that not has a DNA”.
The things to consider are that the interpretation
is not part of the formal system and there is no way,
from the point of view of the system, to know the
meaning of the sentences.
6 THE CONCEPTION OF
LANGUAGE
In, for example, physics, language is not defined and
is considered as being outside the domain of the
discipline. Even in logic, language is considered
outside the domain of the discipline. Shoenfield
(1967, p.4) characterize language in the following
way:
“We consider a language to be completely
specified when its symbols and formulas are
specified. This makes a language a purely
syntactical object. Of course most of our
languages will have a meaning (or several
meanings); but the meaning is not considered to
be part of the language.”
This is a completely fragmentable view of
language in which the interpretation part and the
description part is outside the language. It is a
distorted approach which, however, has its origin in
the need of separating syntax from semantics in
order to make the concept of proof unambiguous.
For a proof it is of course important not to rely on
our beliefs. However, this view makes language
stunted and we may ask from where the
interpretation comes. The answer is that this process
is a non-fragmentable part of the language itself. A
full language, like a natural language, consists of
description, interpretation, an interpretation process
and a description process. In a full fledge language,
the parts are indivisible. In this holistic view,
language is a wholeness that can not be broken into
parts without being distorted. This is the holistic
view of language as formulated by Löfgren (1991):
“In no language, its interpretation process can be
completely described in the language itself.”
Unlike classical physics, language is impossible
to completely objectify in itself. Understanding of a
language is understanding of both form and meaning
in a complementary conception in which
fragmentation into parts does not succeed. When we
say that language is holistically considered or we say
that interpretations are non-linguistic entities or even
extra-linguistic entities, the result is the same,
namely that the interpretation of sentences does not
belong to the realm of sentences: a complete
epistemological description of a language L cannot
be given in the same language L, because the
concept of truth of sentences of L cannot be defined
in L.
The interpretation of a language makes the
concepts and the concepts we perceive give the
language. That is why we cannot objectify language
as is possible with objects in (classical) physics. We
cannot go outside the language but have to stay
within it; we are imprisoned in our own language.
As soon as we are trying to describe a language,
fragmentation is a necessity. Depending upon
whether an attempted fragmentation is thought of in
ontological and semantic terms or in epistemological
and descriptive terms, different complementarity
views results. According to Löfgren (1992), “the
fragmentation types are not independent, and an
autological closure onto language, in its ultimate
wholistic conception, will yield a general type of
complementarity, to which other can be reduces”.
7 COMPUTERS AS
INTERPRETERS
Two things are essential for a computer to be a
formal system. Firstly, every formula should be
possible to be coded in numbers. Secondly, the
mechanical procedure, referred to above, should be
recursive. Gödel (1951) explains it as follows:
“This concept [formal system] is equivalent to
the concept of “computable function of integers”
[…] The procedures to be considered do not
operate on integers but on formulas, but because
of the enumeration of the formulas in question,
they can always be reduced to procedures
operating on integers.”
By way of an example, let
),(
21
2
1
xxA be the
first two-place predicate symbol (in a list), then one
way of coding it is to the number
2
99
3
3
5
21
7
7
11
29
13
5
. (Mendelson, 1964, p. 191)
It is the mechanical characteristics of inference
rules that make a computer a formal system. With an
inference rule is attached an action (interpretation),
namely a new sentence that is produced from the old
sentences. As an action it cannot fully be described
in terms of axioms (sentences) alone. Without such a
SEMIOTICS, MODELS AND COMPUTING
287
complementary action, a theory
3
, with an infinite set
of theorems could not be finitely represented and
thus not communicated. This is in complete accord
with Gödel’s answer to a question of Burks
(Neumann, 1966, p. 55) “The complete description
of its [Turing machine, BE] behaviour is infinite
because, in view of the non-existence of a decision
procedure predicting its behavior, the complete
description could be given only by an enumeration
of all instances.”
8 CONCLUSIONS
The action of a computer is an act of interpretation
operating on numbers representing sentences. This
action cannot itself be reduced to sentences (axioms)
in the given logical language. There must always be
a production of new sentences from others. It is in
this sense that a computer is a linguistic system: a
behavior of a computer system is an interpretation of
its description.
Since the interpretation process is outside the
description (program), no computer will ever
simulate, in an acceptable way, a semiotic system.
This is prohibited by the complementarity view of
language, because if the linguistic complementarity
would be possible to invalidate, then the holistic
language phenomenon would not exist.
Interpretation should disappear and communication
would be completely syntactic. Uncomputability
would be a for ever unknown concept for such
beings.
Computer systems should be seen as the
linguistic systems they are with a well defined
model. It is the model, preceding the construction of
a program, that should be well communicated and
may very well benefit from semiotic methods.
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