Jon Alan Schmidt, list,

Peirce adopted the old distinction between /logica docens/ and /logica utens/ and made no notable modification in it. /Logica docens/ is formal and systematic, while /logica utens/ is informal and is not systematically studied. See at Commens.org:

   1901 | The Proper Treatment of Hypotheses: a Preliminary Chapter,
   toward an Examination of Hume's Argument against Miracles, in its
   Logic and in its History | HP 2:891-892

   … the classification of arguments is the chief business of the
   science of logic; so that every man who reasons (in the above sense)
   has necessarily a rudimentary science of logic, good or bad. The
   slang of the medieval universities called this his _/logica utens/_,
   - his “logic in possession”, - in contradistinction to _/logica
   docens/_, or the legitimate doctrine that is to be learned by study.

See under "/Logica Docens/" which has the above and two other quotes from Peirce about it.

http://www.commens.org/dictionary/term/logica-docens

Best, Ben

On 9/3/2019 10:10 PM, Jon Alan Schmidt wrote:
Ben U., List:

It depends on what exactly we mean by "mathematics of logic."  Peirce used that specific term only once in CP/EP (1.185/2:259, 1903) and twice in NEM (1:256, no date; 3:333, 1903).  In all three cases, he was referring to the very first branch of the very first science, Mathematics--i.e., what he elsewhere called "mathematical logic" or "formal logic," distinguishing this as "the science which /draws /necessary conclusions" from deductive logic as "the science of /drawing /necessary conclusions" (CP 4.239-240; 1902).  To me, that seems directly parallel to the distinction that he drew elsewhere between /logica utens/ and /logica docens/.

    CSP:  But mathematics performs its reasonings by a /logica utens/
    which it develops for itself, and has no need of any appeal to a
    /logica docens/; for no disputes about reasoning arise in
    mathematics which need to be submitted to the principles of the
    philosophy of thought for decision. (CP 1.417; c. 1896)


I take "the philosophy of thought" in this context to mean what Peirce later identified as the Normative Science of "logic proper" or "formal semeiotic."

Regards,

Jon S.

On Tue, Sep 3, 2019 at 8:41 PM Ben Udell <[email protected] <mailto:[email protected]>> wrote:

    Jon A.S., list,

    I agree, Peirce doesn't say or imply that there is or ought to be
    a discipline of formal semiotic between phaneroscopy and the
    normative areas esthetics, ethics, logic.

    However, mathematics of logic in Peirce's sense seems /logica
    docens/, not as you call it /logica utens/. /Docens/, because it's
    explicit and theoretical, not to mention rather formal.

    Best, Ben

    On 9/3/2019 9:31 PM, Jon Alan Schmidt wrote:
    Ben U., List:

    Thanks for this correction; I need to remember to include NEM
    whenever I undertake terminological searches in the future. 
    Fortunately for me, these earlier passages (1902) are consistent
    with what I have been saying all along--Formal Semeiotic is
    simply how Peirce defined Logic, which is the third branch of
    Normative Science in his 1903 classification.  It certainly /does
    not/ fall under Phenomenology.

    No one is claiming that "the mathematics of logic" or
    "mathematical logic" is limited to /deductive /logic.  It is
    simply the /logica utens/ that is required for /every /science,
    including the other branches of Mathematics, Phenomenology,
    Esthetics, and Ethics.  Logic proper--Formal Semeiotic--provides
    a /logica docens/ by studying the process of reasoning
    (semeiosis), including the relation between signs and the end of
    truth, which is why it is a /Normative /Science.

    Regards,

    Jon Alan Schmidt - Olathe, Kansas, USA
    Professional Engineer, Amateur Philosopher, Lutheran Layman
    www.LinkedIn.com/in/JonAlanSchmidt
    <http://www.LinkedIn.com/in/JonAlanSchmidt> -
    twitter.com/JonAlanSchmidt <http://twitter.com/JonAlanSchmidt>

    On Tue, Sep 3, 2019 at 7:58 PM Ben Udell <[email protected]
    <mailto:[email protected]>> wrote:

        Jon A.S., John F.S., list,

        On 9/3/2019 1:53 PM, Jon Alan Schmidt wrote:

        JAS:  [...] there is no passage whatsoever where he employed
        the term "Formal Semeiotic," [....]

        /Au contraire/ (variant spellings notwithstanding),

        http://www.iupui.edu/~arisbe/menu/library/bycsp/L75/ver1/l75v1-05.htm

            QUOTE:
            Final Version of the Carnegie application - MS L75.363-364
            MEMOIR   12
            ON THE DEFINITION OF LOGIC

            Logic will here be defined as formal semiotic.  A
            definition of a sign will be given which no more refers
            to human thought than does the definition of a line as
            the place which a particle occupies, part by part, during
            a lapse of time. Namely, a sign is something, A, which
            brings something, B, its interpretant sign determined or
            created by it, into the same sort of correspondence with
            something, C, its object, as that in which itself stands
            to C. It is from this definition, together with a
            definition of "formal", that I deduce mathematically the
            principles of logic. I also make a historical review of
            all the definitions and conceptions of logic and show not
            merely that my definition is no novelty, but that my
            non-psychological conception of logic has virtually been
            quite generally held, though not generally recognized.

            From Draft D - MS L75.235-237
            I define logic very broadly as the study of the formal
            laws of signs, or formal semiotic. I define a sign as
            something, A, which brings something, B, its
            interpretant, into the same sort of correspondence with
            something, C, its object, as that in which itself stands
            to C. [....]
            END QUOTE

        These passages are in New Elements of Mathematics, which
        includes a passage (absent from Joe Ransdell's version of the
        Carnegie application) that Jon Awbrey likes to quote (e.g.,
        he put it into the Peirce Wikipedia article on Peirce):

        No. 12. /On the Definition of Logic/ [Earlier Draft]

            QUOTE:
            Logic is /formal semiotic./  A sign is something, A,
            which brings something, B, its /interpretant/ sign,
            determined or created by it, into the same sort of
            correspondence (or a lower implied sort) with something,
            C, its object, as that in which itself stands to C.  This
            definition no more involves any reference to human
            thought than does the definition of a line as the place
            within which a particle lies during a lapse of time.  It
            is from this definition that I deduce the principles of
            logic by mathematical reasoning, and by mathematical
            reasoning that, I aver, will support criticism of
            Weierstrassian severity, and that is perfectly evident.
            The word “formal” in the definition is also defined. 
            (NEM 4, 54).
            END QUOTE.

        As regards mathematics of logic, it's been unclear to me just
        what it consists of.  It's not enough to say, it's all and
        only the deductive logic.  There is deductive math applied in
        philosophy, according to Peirce, e.g. applied as the doctrine
        of chances (probability theory).  Are the existential graphs
        logic applied in philosophy, or are they in Peirce's first
        part of math, called mathematics of logic?  Is maths of logic
        just an algebra of two values /v, f,/ that could stand for
        Caesar, Pompey, (Peirce said something like that), just as
        well as for true (/verum/) and false? There's a passage about
        that where Peirce goes on to discuss triadic mathematics,
        which I didn't understand, I'm no mathematician. There is to
        keep in mind is that the mathematics of logic is not
        necessarily fully the selfsame thing as the logic of
        mathematics. Peirce often discusses how mathematics USES
        diagrammatic reasoning, but usually says that mathematics
        needs, and anyway has taken, no help FROM logic except in a
        few cases, involving infinities if I recall aright.

        Best, Ben

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