Maverick Philosopher

Footnotes to Plato from the foothills of the Superstition Mountains

Category: Logica Docens

  • Validity and Anaphora

    The following argument appears valid: Some deity is called 'Zeus.'Zeus is wise.Therefore, some deity called 'Zeus' is wise. (D. E. Buckner, Reference and Identity, 118) Now if an argument is valid, it is valid in virtue of its logical form.  What is the logical form of the above argument? The following argument-form, Buckner correctly states,…

  • Logical Form, Equivocation, and Propositions

    A re-post with minor edits and additions from 4 September 2017. ……………………………….. Ed Buckner wants to re-fight old battles. I'm game. The following post of his, reproduced verbatim, just appeared at Dale Tuggy's site: The concept of logical form is essential to any discussion of identity, and hence to any discussion of the Trinity. Here is…

  • Circular Definitions, Arguments, and Explanations

    In the course of our discursive operations we often encounter circularity.  Clarity will be served if we distinguish different types of circularity.  I count three types.  We could label them definitional, argumentative, and explanatory. A.  The life of the mind often includes the framing of definitions.  Now one constraint on a good definition is that…

  • A Reader Asks about Existence and Instantiation

    My responses are in blue. Hello, Dr. Vallicella. I am a reader of your blog. I just read your article "Existence: Two Dogmas of Analysis" in Neo-Aristotelian Perspectives in Metaphysics (eds. Novotny and Novak, Routledge, 2014, pp. 45-75 , and I thought it was fantastic. I will have to read it again at some point.…

  • Another Thought on Psychologism in Logic

    Logic is prescriptive and proscriptive.  Logic prescribes how we ought to think if we would arrive at truth. It also proscribes those ways of thinking that lead to error.  But 'ought' implies 'can.' How we ought to think must be really possible, indeed really possible for us, where what is really possible for us is…

  • Has Any Philosophical Problem Been Solved? The case of psychologism in logic.

    For Cyrus …………… A reader is skeptical of my solubility skepticism. He adduces the problem of psychologism in logic which, he suggests, has been definitively settled in favor of the anti-psychologizers.  Here, then, is a problem that supposedly has been solved. There is progress in philosophy after all. My reader is joined by Robert Spaemann…

  • First and Second Intentions: Buckner on Zabarella, Kant, Frege, and Wittgenstein

    The following two quotations are from the Facebook Medieval Logic forum.   Giacomo Zabarella (1533 – 1589). “Now first intentions are names immediately signifying realities by means of a concept in the soul, for instance, animal and human being, or those concepts of which these names are signs. But second intentions are other names imposed…

  • How Much Logic Do I Need?

    A reader who reports that his main interest is in contemporary metaphysics inquires: Should I learn as much logic as humanly possible during my PhD? Or should I learn only what I need along the way? I have a basic grasp of symbolic and predicate logic, but little meta-logic. First of all, it makes no…

  • Truth and Falsity from a Deflationary Point of View

    The following equivalence is taken by many to support the deflationary thesis that truth has no substantive nature, a nature that could justify a substantive theory along correspondentist, or coherentist, or pragmatic,  or other lines.  For example, someone who maintains that truth is rational acceptability at the ideal (Peircean) limit of inquiry is advancing a…

  • Excluded Middle, Presentism, Truth-Maker: An Aporetic Triad

    Suppose we acquiesce in the conflation of Excluded Middle and Bivalence.  The conflation is not unreasonable.  Now try this trio on for size: Excluded Middle: Every proposition is either true, or if not true, then false.Presentism: Only what exists at present, exists.Truth-Maker: Every contingent truth has a truth-maker. The limbs of the triad are individually…

  • Excluded Middle, Bivalence, and Disquotation

    LEM: For every  p, p v ~p. BV: Every proposition is either true or false. These principles are obviously not identical.  Excluded Middle is syntactic principle, a law of logic, whereas Bivalence is a semantic principle. The first says nothing about truth or falsity. The second does. (See Michael Dummett, Truth and Other Enigmas, Harvard…

  • Excluded Middle, Bivalence, and Tertium Non Datur

    Dave Gudeman comments: I was surprised to see you distinguishing between bivalence and the LEM. As far as I can tell, in the traditional and most common formulations, they are identical. Here is the way I understand it.  They are not identical.  Excluded Middle is a law of logic, whereas Bivalence is a semantic principle.…

  • Atomic Sentences and Syncategorematic Elements

    The Ostrich tells me that Frege has no copula. That's not wrong, but there is a nuance that muddies the waters. Suppose Al is fat. The symbolization as Fa suggests the absence of a copula and thus the absence of a syncategorematic element. There appears to be only two categorematic elements, a and F. Well,…

  • Presupposition and Excluded Middle

    If Socrates dies at time t, then Socrates was alive prior to t. If Socrates does not die at t, then Socrates was alive prior to t.  Since both 'Socrates dies at t' and 'Socrates does not die at t' entail 'Socrates was alive prior t,' we say that the latter is a semantic presupposition…

  • Is Assertion Closed Under Entailment? Assertion and Presupposition

    Suppose a person asserts that p. Suppose also that p entails q. Does it follow that the person asserting that p thereby asserts that q?  If so, and if p and q are any propositions you like, then assertion is closed under entailment.  If assertion is not closed under entailment, then there will be examples…