The following passage is very instructive on several points, illuminating especially the relationship between interpreters (sign-using agents) and interpretant signs.
We are all, then, sufficiently familiar with the fact that many words have much implication; but I think we need to reflect upon the circumstance that every word implies some proposition or, what is the same thing, every word, concept, symbol has an equivalent term — or one which has become identified with it, — in short, has an interpretant.
Consider, what a word or symbol is; it is a sort of representation. Now a representation is something which stands for something. I will not undertake to analyze, this evening, this conception of standing for something — but, it is sufficiently plain that it involves the standing to something for something. A thing cannot stand for something without standing to something for that something. Now, what is this that a word stands to? Is it a person?
We usually say that the word homme stands to a Frenchman for man. It would be a little more precise to say that it stands to the Frenchman’s mind — to his memory. It is still more accurate to say that it addresses a particular remembrance or image in that memory. And what image, what remembrance? Plainly, the one which is the mental equivalent of the word homme — in short, its interpretant. Whatever a word addresses then or stands to, is its interpretant or identified symbol. Conversely, every interpretant is addressed by the word; for were it not so, did it not as it were overhear what the word says, how could it interpret what it says.
There are doubtless some who cannot understand this metaphorical argument. I wish to show that the relation of a word to that which it addresses is the same as its relation to its equivalent or identified terms. For that purpose, I first show that whatever a word addresses is an equivalent term, — its mental equivalent. I next show that, since the intelligent reception of a term is the being addressed by that term, and since the explication of a term’s implication is the intelligent reception of that term, that the interpretant or equivalent of a term which as we have already seen explicates the implication of a term is addressed by the term.
The interpretant of a term, then, and that which it stands to are identical. Hence, since it is of the very essence of a symbol that it should stand to something, every symbol — every word and every conception — must have an interpretant — or what is the same thing, must have information or implication.
(Peirce 1866, Lowell Lecture 7, CE 1, 466–467).
My study of Peirce’s formula — “Information = Comprehension × Extension” — helps to place this passage in context:
There’s additional discussion here:
- Peirce, C.S. (1866), “The Logic of Science, or, Induction and Hypothesis”, Lowell Lectures of 1866, pp. 357–504 in Writings of Charles S. Peirce : A Chronological Edition, Volume 1, 1857–1866, Peirce Edition Project, Indiana University Press, Bloomington, IN, 1982.