Jon AS, list
I changed the subject line to emphasize the conclusion.
To see the evolution of Peirce's ideas, look at the chronological
developments. In 1903, Peirce defined the word 'seme' in a way
that is inconsistent with what he wrote in 1906:
An Index or Seme is a Representamen whose Representative character
consists in it's being an individual Second... (EP 2:274)
But note what he had written in 1902 (CP 2.320):
A man's portrait with a man's name written under it is strictly a
proposition, although its syntax is not that of speech, and although
the portrait itself not only represents, but is, a Hypoicon. But the
proper name so nearly approximates to the nature of an Index, that
this might suffice to give an idea of an informational Index.
A portrait plus an index asserts a proposition (dicisign). In effect,
the image is used as a kind of predicate. In that same paragraph,
he introduced the word 'quasi-predicate' for images used in this way:
A better example is a photograph. The mere print does not, in itself,
convey any information. But the fact, that it is virtually a section
of rays projected from an object otherwise known, renders it a Dicisign.
Every Dicisign, as the system of Existential Graphs fully recognizes,
is a further determination of an already known sign of the same object.
It is not, perhaps, sufficiently brought out in the present analysis.
It will be remarked that this connection of the print, which is the
quasi-predicate of the photograph, with the section of the rays,
which is the quasi-subject, is the Syntax of the Dicisign;
By referring to EGs, Peirce emphasizes the similarity between the
iconic structure of an EG and images of any kind. EGs with pegs
that are not attached to any line of identity represent predicates.
The act of attachment is "a further determination" that converts
a predicate or a quasi-predicate into a dicisign (proposition).
Chronology:
1902: An image is a quasi-predicate when it combines with an index
or quasi-index to state a proposition (dicisign).
1903: An index and a seme are synonymous. That is very different
from his definition of 1906. That implies that (a) Peirce's
terminology was unstable, and (b) the ethics of terminology
does not apply to unstable terms.
1906: A seme is a widening (generalization) of predicate to include
percepts and other image-like signs when used as predicates.
In effect, seme means "predicate or quasi-predicate".
Interpretation: With the prefix 'quasi-', Peirce modified the word
'predicate' for images used as predicates. In 1903, he introduced
the word 'seme' as a synonym for index. But that made it redundant.
When he was writing the Monist article in 1906, he wanted a single
word for both predicates and quasi-predicates. So he dusted off
the word 'seme'. After 1906, he didn't use the word 'seme' because
it was simpler and clearer to use his favorite words 'monad', 'dyad',
'triad'... for both predicates and quasi-predicates.
Summary: Peirce used the word 'predicate' for examples in logic
and ordinary language. He used 'quasi-predicate' for images used
as predicates. In 1906, he used 'seme' as a generalization of
predicate and quasi-predicate.
Conclusion: The evidence from 1906 and later shows that the word
'seme' may be replaced by a word that means "predicate or quasi-
predicate". Therefore, the word 'predicate' may be generalized
to include every use of 'quasi-predicate'. That eliminates any
need for the word 'seme'.
See below for comments about the quotations from 1906 and 1908.
John
______________________________________________________________________
JAS
there is a late passage ... that spells out in considerable detail
what Peirce ultimately considered to be the "proper" logical analysis
of a proposition. In his letter of December 5, 1908 to Jourdain...
No. Definitely not. His existential graphs and diagrammatic
reasoning are the most elegant and powerful basis for his logical
analyses. In fact, they're superior to the systems by Frege,
Russell, Whitehead, and even Gentzen. See the slides for "Peirce,
Polya, and Euclid: Integrating logic, heuristics, and geometry":
http://jfsowa.com/talks/ppe.pdf
In the letter to Jourdain, Peirce was writing for a reader who
was familiar with Aristotelian syllogisms, as taught in textbooks
from the 13th c. to the early 20th c:
A proposition can be separated into a predicate and subjects in more
ways than one... The result is that everything in a proposition that
possibly can should be thrown into the subjects, leaving the pure
predicate a mere form of connection, such as 'is,' 'possesses (as a
character),' 'stands in the dyadic relation _____ to _____ ,' 'and'
= 'is at once _____ and _____ ,' etc. ... (NEM 3:885-886, 1908)
This method of separating a proposition into a predicate and logical
subjects is not meaningful for Peirce's EGs or his 1885 notation for
predicate calculus. For a summary of the patterns for syllogisms,
see slides 15 to 18 of http://jfsowa.com/talks/aristo.pdf
The transformation that Peirce recommended would replace the verb
'breathes' in the sentence "Every mammal breathes oxygen" with
the verb 'is' in "Every mammal is an oxygen-breathing animal."
This transformation causes some "logical subjects" to become complex
expressions, such as "oxygen-breathing animal". In the algebraic
notation, that phrase would be represented by a monadic predicate:
Define P(x) as oxygen_breathing(x) & animal(x).
Such transformations are necessary for applying Aristotle's rules
of inference. But they are unnecessary for Peirce's rules.
JAS
the role of what he had called a Seme in 1906--such as "rose" or
"red"--is to serve as a substitute for any logical subject
The words 'rose' and 'red' would be represented by monadic predicates:
rose(x) and red(x). There is no need for the word 'seme'.
JAS
one of the discarded drafts for "Prolegomena to an Apology for
Pragmaticism."
CSP: The first member of the triplet, the 'Seme,' embraces the
logical Term, the Subject or Object of a sentence, everything of any
kind, be it a man or a scribed character, such as H or Pb, which will
serve, or is supposed to serve, for some purpose, as a substitute for
its Object. It is a Sign which pretends, at least, to intend to be
virtually its Object. (R 295:[28-29]; 1906)
Every seme (logical term) in this quotation can be mapped to
a monadic predicate: man(x), H(x), or Pb(x).
For more examples of semes, note the excerpts from CP 4.539 to 4.550:
CP 4.539: a Percept is a Seme, while a fact of Immediate Perception
or rather the Perceptual Judgment of which such fact is the Immediate
Interpretant, is a Pheme...
This implies that a percept, as an image-like pattern, is a quasi-
predicate at the instant it's perceived. But when the image is
connected with an index in a judgment, the quasi-predicate plus
index states a proposition (pheme).
A late Dynamical Interpretant of the whole complex of Percepts is
the Seme of a Perceptual Universe that is represented in instinctive
thought as determining the original Immediate Object of every Percept.†
Footnote: † I.e., A complex of percepts yields a picture of
a perceptual universe...
Each percept in the complex is a quasi-predicate. The complex of
percepts is a picture (a larger quasi-predicate), which is defined
by a conjunction of all the quasi-percepts for its components.
Finally, and in particular, we get a Seme of that highest of all
Universes which is regarded as the Object of every true Proposition,
and which, if we name it [at] all, we call by the somewhat misleading
title of "The Truth."
This big seme is a picture (quasi-predicate) of everything we think
we know (our beliefs). We call that "The Truth" -- but as Peirce
said, most of it may be true, but we never know how much is false.
CP 4.540: How is it that the Percept, which is a Seme, has for
its direct Dynamical Interpretant the Perceptual Judgment, which
is a Pheme [proposition]? For that is not the usual way with Semes,
certainly. All the examples that happen to occur to me at this moment
of such action of Semes are instances of Percepts, though doubtless
there are others. Since not all Percepts act with equal energy in
this way, the instances may be none the less instructive for being
Percepts. However, Reader, I beg you will think this matter out
for yourself... My opinion is that a pure perceptual Icon -- and
many really great psychologists have evidently thought that Perception
is a passing of images before the mind's eye, much as if one were
walking through a picture gallery...
The phrase "Reader, I beg you will think this matter out" and the
dots for another tentative passage indicate that Peirce was still
rethinking these issues. The absence of later writings that use
the word 'seme' suggests that he came to prefer other terminology.
CP 4.550: In one of the narrowest and most concrete of its logical
meanings, a Mind is that Seme of The Truth, whose determinations
become Immediate Interpretants of all other Signs whose Dynamical
Interpretants are dynamically connected.†
Footnote: † i.e. Mind is a propositional function of the widest
possible universe such that its values are the meanings of all
signs whose actual effects are in effective intercommunication.
This seme could be a mental image (quasi-predicate) of all aspects of
an imagined world. If represented symbolically, it would be a very
large predicate. That world could be some individual's view of the
actual world or some imaginary world. With indexes that relate parts
of it to the real world, it would be a proposition that states
everything that some individual knows.
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