Peirce's semeiotic as a foundation for ontology
In many messages, I have claimed that Peirce's writings
are fundamental to the problems of ontology. These remarks
triggered several responses in another forum, and I have
excerpted, revised, and assembled my replies in the
following summary.
John Sowa
__________________________________________________________
Everything that is perceived is perceived by means of a sign,
which may be just a sign of itself. But more likely it is
a sign of just some aspect of the thing, such as an image,
a feeling, a change in temperature, pressure, sweetness,
salinity, etc.
> But there are things that are merely things.
That may be true, but they cannot be *known* unless they are
(a) perceived by their signs, (b) interpreted by means of
other signs (e.g., percepts, concepts, words, sentences, etc.),
and (c) tested by means of actions to determine their nature.
See Section 7 of the theories.htm paper:
http://www.jfsowa.com/logic/theories.htm
Theories, Models, Language, Reasoning, and Truth
> There are things that are also signs of other things.
That requires further qualifications. When the Mayan ruins
were first explored, the symbols that represented words could
not be distinguished from mere decorations, which are signs
of a different sort. And even when writing is recognized as
writing, it can also be interpreted in many different ways,
including decoration (calligraphy). Even when the writing
is known to be writing, its meaning may be ignored for many
purposes, such as transmission across a network.
What we are fundamentally dealing with are signs. There is
no question that there does exist something independent of our
minds, but what it is can only be experienced through signs,
analyzed by means of signs, and classified by means of signs.
> "Is your definition of "sign" stipulative, lexical,
> theoretical, precising, or what?"
I base my discussion on Peirce's semiotics (or semeiotic as he
called it). Following are two slides from another talk, which
summarize the terminology:
____________
*Peirce's Semiotics*
Any perceptible configuration of the universe may be
interpreted as a sign by someone or something.
Basic classification of signs:
* Mark — any pattern in any modality that someone
or something is capable of perceiving.
* Token — a classification of some mark as an instance
of some type.
* Type — a general pattern associated with some schema
or rule for classifying and relating the marks in the
environment.
Example: A mark may be a pattern of green and yellow in
the lawn. The mark may be interpreted as a token of type
Plant, Weed, Flower, SaladGreen, Dandelion, etc.
_____________
*Icon, Index, Symbol*
All living organisms from bacteria to humans process signs.
A sign may be characterized by the way the mark determines
the referent:
* Icon — according to some similarity of image, pattern,
or structure.
* Index — according to some physical relationship;
e.g., immediate presence, pointing to something remote,
or causally indicating something not directly perceptible.
* Symbol — according to some convention; e.g., spoken words,
written words, money, flag, uniform...
Communication, memory, learning, and reasoning depend on signs,
but most signs are not symbols.
_________
> Should we not, in this forum, stick to the "immediate" facts
> and arguments, rather than appealing to historical positions
> or other papers?
What immediate facts? Our only immediate facts are that our
senses can very easily be deceived when we only have one look.
But if we have a chance to check and test our first impressions
by repeated study -- using multiple senses, coming back repeatedly,
etc. -- then we have a much better chance of getting an accurate
picture. That indicates that we need multiple *signs* preferably
from different modalities in order to form a sound judgment.
Psychological studies have provided abundant evidence of how
children and young animals require multiple sensory modalities
in order to form an accurate model of reality. Sensory deprivation
studies on children are unethical, but such studies have been
performed on cats and other animals to demonstrate that sight
alone without confirmation by touching is insufficient to enable
the animal to form an accurate model of 3-D relationships.
To separate the entangled points in a more extended summary,
let me start with a description of the processes of perception
along the lines that cognitive psychologists have been discussing
for the past 40 years or so. This position, by the way, is very
different from the behaviorist views in the first half of the
20th century, but it is not very far from the position that
William James presented in 1895.
1. Incoming signals that impinge on our nerve endings are signs.
2. Perception involves the interpretation of those signs by
a process of retrieving one or more chunks of previously
experienced signs (traditionally called _percepts_) that
are assembled into a pattern that matches the new signs.
3. The process of perception is rarely an exact match of
old percepts to new signs. Instead, the assembly of
percepts has the nature of a hypothetical construction,
which may involve a considerable amount of deformation
and adjustment. The process is definitely fallible and
possibly ambiguous, in the sense that several different
selections of percepts could be adapted to match the
any given incoming pattern of signs.
4. Peirce called the process of perception a kind of abduction,
and that term has been applied by computational linguists,
such as Jerry Hobbs, to the process of parsing natural language
sentences (which are usually processed by methods similar to
the steps outlined in #2 and #3 above).
5. Not all percepts are associated with words in a natural
language, but many of them are. A natural language description
of the perceived experience could be generated by assembling
the words that correspond to the percepts in an NL sentence
according to the syntax of the language and with the help of
auxiliary morphemes, such as function words and inflections.
Assuming a process of perception of this sort (which is a common
hypothesis in cognitive psychology), I would expand my earlier
summary thus: the process of perception involves the matching
of incoming signs to a hypothetical construction from stored
percepts. The pattern matching process is fallible, and any
particular construction is a hypothesis that could be, and
often is, falsified or at least corrected by future experience.
What we call "objects" are the external projections of our
internal constructions that have proved to be useful over long
periods of time. Peirce said that a great many of our beliefs
that have survived extensive testing are probably true within
the limits of our ability to perceive and verify. We can
probably be sure that our cherished beliefs will survive tests
that are similar to our past experiences, but we can never
be certain how far they can be trusted.
Note the ubiquitous signs: the original signals from the nerve
endings, the store of percepts in the brain, the assemblies of
percepts used to interpret the new signs, the stable constructions,
which we call "objects", and the words and sentences we use to
describe them. They're all signs.
> But what are the signs just before they impinge on our
> nerve endings?
Anything that does not impinge, has not yet impinged, or is
not capable of affecting our nerve endings is an undetected
part of the environment. Using telescopes, microscopes, and
other instruments, we can detect aspects of the environment
that are beyond the reach of our senses.
When I said "someone or something", I intended the something
to be an organism that could be as lowly as a bacterium or
some sort of humanly designed instrument that serves as an
extension or a surrogate for our nervous system.
As soon as those environmental features are detected by the
nerves or instruments, they may be called "marks", which are
the most basic signs. A mark does not become a token until
it is interpreted as an instance of some type.
JS>> What we call "objects" are the external projections of our
>> internal constructions that have proved to be useful over long
>> periods of time.
> Were the unicellular organisms existing billions of years ago
> already then objects?
The organisms are the things that are doing the perceiving. The
things that are perceived could be called by many different terms,
including objects, processes, stimuli, etc. Since bacteria don't
have language, they don't call them anything, but they classify
the marks as tokens according to types, which we may call food,
nourishment, poison, danger, threat, etc. By their behavior,
we can observe the responses that indicate how they classify
various stimuli according to the types that we identify.
JS>> Different psychologists may have different theories and
>> different terminology for the processes of perception, but
>> what they're discussing is still signs and signs of signs.
> Did we evolve from signs and signs of signs?
Our bodies evolved from other bodies, but our minds evolved
from more primitive sign-processing minds or quasi-minds of
simpler organisms. A few million years ago, they were apes,
which are extremely human-like except for linguistic ability.
A few billion years ago, they were some sort of unicellular
organisms, for which Peirce coined the term "quasi-mind".
Peirce made the point that every thought, idea, concept, or
percept is a sign and that the mind is a complex sign composed
of the totality of all the simpler signs that flow through it.
That, in short, is Peirce's solution to the so called mind-body
problem: Instead of postulating an unbridgeable gap between
an abstract mind and a physical body, Peirce developed a theory
of the way physical sign tokens are classified by abstract
sign types. The mind and its contents can be classified
according to abstract sign types, but it and its contents
are embodied in tokens of those types.