John, I notice that you haven’t supplied what I asked for, “any Peirce text on EGs where he refers to a Spot with one Tail, or a Line of Identity by itself, as a "Medad".
I’m also having trouble reconciling your usage of the term “peg” with Peirce’s. In Peirce, it’s a Spot that has Pegs, so that a Spot with its Pegs represents a rheme with its blanks: [[ By a rheme, or predicate, will here be meant a blank form of proposition which might have resulted by striking out certain parts of a proposition, and leaving a blank in the place of each, the parts stricken out being such that if each blank were filled with a proper name, a proposition (however nonsensical) would thereby be recomposed. An ordinary predicate of which no analysis is intended to be represented will usually be written in abbreviated form, but having a particular point on the periphery of the written form appropriated to each of the blanks that might be filled with a proper name. Such written form with the appropriated points shall be termed a Spot; and each appropriated point of its periphery shall be called a Peg of the Spot. If a heavy dot is placed at each Peg, the Spot will become a Graph expressing a proposition in which every blank is filled by a word (or concept) denoting an indefinite individual object, “something.” ] CP 4.560 (Prolegomena, 1906) ] If the heavy dot placed at a Peg is extended, it becomes a Line of Identity, with a Loose End if it is unattached at the other extremity. This is what Peirce sometimes calls “a Spot with one Tail,” which is a Monad, not a Medad. A Line of Identity does not have Pegs; it’s the Spots that have Pegs, and the only kind of “Spot” that does not represent a rheme is the “Spot of Teridentity” (CP 4.561). As you quoted, “"A graph or graph instance having 0 peg is a Medad."” But Peirce doesn’t apply this terminology to a Line of Identity, even if it is considered as a graph instance by itself. It’s the predicate/rheme/Spot that has a valency, and it’s the valency that constitutes the -adicity of the graph: [[ We call a Spot a Medad, Monad, Dyad, Triad, Tetrad, or by some other such name, according as its Valency, or the number of its Pegs, is 0, 1, 2, 3, 4, etc. ] R 293, 1906] This is confirmed in the 1906 Welby letter that I posted awhile back at http://gnusystems.ca/PeirceWelbyMarch1906.htm, where a Spot with one peg (i.e. one line of identity attached) is labelled a “monad.” Your calling it a “medad” therefore requires some explanation, as does your statement that a particular graph is “a medad because it has no unattached peg.” I can’t make sense of the term “unattached peg.” I raise the matter because it has implications for phaneroscopy as well as EGs. Gary f. -----Original Message----- From: John F Sowa <[email protected]> Sent: 20-Mar-19 16:15 To: [email protected] Subject: Re: [PEIRCE-L] The Bedrock Beneath Pragmaticism On 3/20/2019 11:37 AM, <mailto:[email protected]> [email protected] wrote: > I thought a Medad was (by definition) a graph with no loose ends. NEM 3:164 (or p. 4 of eg1911.pdf) says "A graph or graph instance having 0 peg is a Medad." There are many places were Peirce says that a line of identity, by itself asserts "Something exists." Don Roberts (p. 47) discusses this point in some detail, and cites some references. Since a line of identity is an EG and it has 0 peg, it's a medad. Roberts (p. 48) discusses many EGs that have a line with one loose end. In eg1911.pdf, Fig. 1 for There is something that is not a phoenix" has one loose end for "something". It's also a medad because it has no unattached peg. John
----------------------------- PEIRCE-L subscribers: Click on "Reply List" or "Reply All" to REPLY ON PEIRCE-L to this message. PEIRCE-L posts should go to [email protected] . To UNSUBSCRIBE, send a message not to PEIRCE-L but to [email protected] with the line "UNSubscribe PEIRCE-L" in the BODY of the message. More at http://www.cspeirce.com/peirce-l/peirce-l.htm .
