An argument […] is nearly equivalent to “premiss” or “copulate premiss,” i.e. a body of premisses having a single intention, and is a known or pretended fact which is intended to serve as a Sign of the reality of another fact, its Conclusion.
A familiar logical triplet is Term, Proposition, Argument. In order to make this a division of all signs, the first two members have to be much widened. [—] As the third member of the triplet, I sometimes use the word Delome […], though Argument would answer well enough. It is a Sign which has the Form of tending to act upon the Interpreter through his own self-control, representing a process of change in thoughts or signs, as if to induce this change in the Interpreter.
I […] define an argument as a sign which is represented in its signified interpretant not as a Sign of the interpretant (the conclusion) [for that would be to urge or submit it] but as if it were a Sign of the Interpretant or perhaps as if it were a Sign of the state of the universe to which it refers, in which the premisses are taken for granted.
A representamen is either a rhema, a proposition, or an argument. An argument is a representamen which separately shows what interpretant it is intended to determine. A proposition is a representamen which is not an argument, but which separately indicates what object it is intended to represent. A rhema is a simple representation without such separate parts.
An Argument is a sign whose interpretant represents its object as being an ulterior sign through a law, namely, the law that the passage from all such premisses to such conclusions tends to the truth. Manifestly, then, its object must be general; that is, the Argument must be a Symbol. As a Symbol it must, further, be a Legisign. Its Replica is a Dicent Sinsign.