Below are some philosophy papers of mine to download. None of them are about pumpkins and there aren't even any examples involving pumpkins in them, sadly.
Coming soon: 1. a paper on negation and incompatibility; 2. a paper on the prooftheory of normal modal logics; 3. a formal paper proving a theorem on extensions of intuitionist logic to classical logic with philosophical applications to the theory of meaning; 4. a counterexample to Lewis' semantics for counterfactuals, that shows in a really simple and clear fashion that the logic of counterfactuals should be more like what Lewis thinks is mere relative necessity. There is also a paper on a pragmatic justification of logical pluralism somewhere on my hard disc, and I have a draft of a paper on Aristotle on the Law of NonContradiction, which I hope to finish at some point. I think there is a pretty remarkable argument in Metaphysics Gamma, but for the moment, I feel overwhelmed by the depth of Aristotle's thought and my lack of knowledge of his overall philosophical outlook. My next long term research project is the prooftheory of modal logic. I learnt that there is something called The Great Pumpkin objection in epistemology and the philosophy of religion. That's brilliant. Right up my street. One day I'll have to write a paper on it. I already have a title: 'The Great Pumpkin's Objection to the Great Pumpkin Objection'. I published one of my articles in Kindle format, mostly for fun, but if inadvertently I make a fortune out of it, I won't complain. You can buy it here: "Negation: A Problem for the ProofTheoretic Justification of Deduction". I once won the Jacobsen Essay Prize of the University of London for it. Surely worth a few quid, I'd say. 
The Importance of Being Erroneous
This is a commentary on MM McCabe's "First Chop your logos... Socrates and the sophists on language, logic, and development". In her paper MM analyses Plato's Euthydemos, in which Plato tackles the problem of falsity in a way that takes into account the speaker and complements the Sophist's discussion of what is said. The dialogue looks as if it is merely a demonstration of the silly consequences of eristic combat. And so it is. But a main point of MM's paper is that there is serious philosophy in the Euthydemos, too. MM argues that to counter the sophist brothers Euthydemos and Dionysodoros, Socrates points out that that there are different aspects to the verb 'to say' that run in parallel to the different aspects of the very 'to learn'. So just as there is continuity rather than ambiguity between 'to learn' and 'to understand', so there is continuity between the different aspects of saying. Thus Socrates puts forward a teleological account of both learning and meaning. Following up on some of MM's thoughts, I argue that the sophists have, despite appearance, a theory of meaning that respects serious and widely accepted philosophical theses on meaning, Forthcoming in the Australasian Philosophical Review. The curator of the volume is Fiona Leigh, and the committee also has Hugh Benson and Tim Clarke. You can find MM's paper as well as the commentaries by Nicholas Denyer and Russell E. Jones and Ravi Sharma (and myself) by registering. 
Nils Kürbis: George Molnar on Truthmakers for Negative Truths
Molnar argues that the problem of truthmakers for negative truths arises because we tend to accept four metaphysical principles that entail that all negative truths have positive truthmakers. This conclusion, however, already follows from only three of Molnar's metaphysical principles. One purpose of this note is to set the record straight. I provide an alternative reading of two of Molnar's principles on which they are all needed to derive the desired conclusion. Furthermore, according to Molnar, the four principles may be inconsistent. By themselves, however, they are not. The other purpose of this note is to propose some plausible further principles that, when added to the four metaphysical theses, entail a contradiction. Forthcoming in Metaphysica, ArticleDOI: 10.1515/mp20180014 

Nils Kürbis: Bilateralism: Negations, Implications and some Observations and Problems about Hypotheses This short paper has two loosely connected parts. In the first part, I discuss the difference between classical and intuitionist logic in relation to different the role of hypotheses play in each logic. Harmony is normally understood as a relation between two ways of manipulating formulas in systems of natural deduction: their introduction and elimination. I argue, however, that there is at least a third way of manipulating formulas, namely the discharge of assumption, and that the difference between classical and intuitionist logic can be characterised as a difference of the conditions under which discharge is allowed. Harmony, as ordinarily understood, has nothing to say about discharge. This raises the question whether the notion of harmony can be suitably extended. This requires there to be a suitable fourth way of manipulating formulas that discharge can stand in harmony to. The question is whether there is such a notion: what might it be that stands to discharge of formulas as introduction stands to elimination? One that immediately comes to mind is the making of assumptions. I leave it as an open question for further research whether the notion of harmony can be fruitfully extended in the way suggested here. In the second part, I discuss bilateralism, which proposes a wholesale revision of what it is that is assumed and manipulated by rules of inference in deductions: rules apply to speech acts – assertions and denials – rather than propositions. I point out two problems for bilateralism. First, bilaterlists cannot, contrary to what they claim to be able to do, draw a distinction between the truth and assertibility of a proposition. Secondly, it is not clear what it means to assume an expression such as '+ A' that is supposed to stand for an assertion. Worse than that, it is plausible that making an assumption is a particular speech act, as argued by Dummett (Frege: Philosophy of Language, p.309ff). Bilaterlists accept that speech acts cannot be embedded in other speech acts. But then it is meaningless to assume + A or − A. Published in Beyond Logic. Proceedings of the Conference held in CerisylaSalle, 2227 May 2017, edited by Jean Fichot and Thomas Piecha 

Nils Kürbis: Bilateralist Detours. From Intuitionist to Classical Logic and Back
There is widespread agreement that while on a Dummettian theory of meaning the justified logic is intuitionist, as its constants are governed by harmonious rules of inference, the situation is reversed on Huw Price's bilateralist account, where meanings are specified in terms of primitive speech acts assertion and denial. In bilateral logics, the rules for classical negation are in harmony. However, as it is possible to construct an intuitionist bilateral logic with harmonious rules, there is no formal argument against intuitionism from the bilateralist perspective. Price gives an informal argument for classical negation based on a pragmatic notion of belief, characterised in terms of the differences they make to speakers' actions. The main part of this paper puts Price's argument under close scrutiny by regimenting it and isolating principles Price is committed to. It is shown that Price should draw a distinction between A or ¬A making a difference. According to Price, if A makes a difference to us, we treat it as decidable. This material allows the intuitionist to block Price's argument. Abandoning classical logic also brings advantages, as within intuitionist logic there is a precise meaning to what it might mean to treat A as decidable: it is to assume A ∨ ¬A. Published in Logique et Analyse 60 (2017): 301316 

Nils Kürbis: Some Comments on Ian Rumfitt's Bilateralism
Ian Rumfitt has proposed systems of bilateral logic for primitive speech acts of assertion and denial, with the purpose of 'exploring the possibility of specifying the classically intended senses for the connectives in terms of their deductive use'. Rumfitt formalises two systems of bilateral logic and gives two arguments for their classical nature. I assess both arguments and conclude that only one system satisfies the meaningtheoretical requirements Rumfitt imposes in his arguments. I then formalise an intuitionist system of bilateral logic which also meets those requirements. Thus Rumfitt cannot claim that only classical bilateral rules of inference succeed in imparting a coherent sense onto the connectives. My system can be extended to classical logic by adding the intuitionistically unacceptable half of a structural rule Rumfitt uses to codify the relation between assertion and denial. Thus there is a clear sense in which in the bilateral framework, the difference between classicism and intuitionism is not one of the rules of inference governing negation, but rather one of the relation between assertion and denial. Keywords: Negation, denial, prooftheoretic semantics, harmony, classical logic, intuitionist logic Published in the Journal of Philosophical Logic 45 (2016): 623644 

Nils Kürbis: Review of Bob Hale's Necessary Beings
I summarise the main strands of Hale's Fregean approach to metaphysics and his views on fundamental modal facts. At the request of the author, I mention an error that will be corrected in the paper back edition. Hale originally thought that on his semantics, where secondorder variables range only over definable subsets of the domain, compactness, completeness, and the LöwenheimSkolem Theorems hold, as they do in the nonstandard Henkin semantics, while categoricity fails. I chose a few issues for closer and critical discussion that I found particularly interesting and worth developing. I think that Hale's new amendment of his well known inferential tests for singular terms is slightly underdeveloped, as it lacks an account of immediate inferences. I suggest that there is an omission in Hale's falsity conditions for the counterfactuals and that Hale's preferred counterfactual logic should turn out to be an analogue of Lewis's VWU, based on Hale's alternative semantics in terms of possibilities rather than possible worlds. Hale defines necessity in terms of counterfactuals, but I question whether we understand counterfactuals as well as we understand necessity, possibility and contingency. I end with the suggestion that Hale's metaphysics can be used to motivate an idea put forward by Arthur Prior: to introduce a new kind of expression into the modal language, often called nominals, which name possibilities, and to adopt hybrid modal logics. The full title of Bob Hale's book is Necessary Beings: An Essay on Ontology, Modality, and the Relations Between Them, published by Oxford University Press. Published in Disputatio VII, No. 40 (2015): 92100 

Nils Kürbis: What is wrong with Classical Negation?
The focus of this paper are Dummett's meaningtheoretical arguments against classical logic based on consideration about the meaning of negation. Using Dummettian principles, I shall outline three such arguments, of increasing strength, and show that they are unsuccessful by giving responses to each argument on behalf of the classical logician. What is crucial is that in responding to these arguments a classicist need not challenge any of the basic assumptions of Dummett's outlook on the theory of meaning. In particular, I shall grant Dummett his general bias towards verificationism, encapsulated in the slogan 'meaning is use'. The second general assumption I see no need to question is Dummett's particular breed of molecularism. Some of Dummett's assumptions will have to be given up, if classical logic is to be vindicated in his meaningtheoretical framework. A major result of this paper will be that the meaning of negation cannot be defined by rules of inference in the Dummettian framework. Keywords: Prooftheoretic semantics, harmony, negation, ex falso quodlibet, compositionality, molecular theories of meaning Published in Grazer Philosophische Studien 92 (2015): 5186 

Nils Kürbis: ProofTheoretic Semantics, a Problem with Negation and Prospects for Modality
This paper discusses prooftheoretic semantics, the project of specifying the meanings of the logical constants in terms of rules of inference governing them. I concentrate on Michael Dummett’s and Dag Prawitz’ philosophical motivations and give precise characterisations of the crucial notions of harmony and stability, placed in the context of proving normalisation results in systems of natural deduction. I point out a problem for defining the meaning of negation in this framework and prospects for an account of the meanings of modal operators in terms of rules of inference. Keywords: ProofTheoretic Semantics, Harmony, Stability, Negation, Modality Published in the Journal of Philosophical Logic 44 (2015): 713727 

Nils Kürbis: How Fundamental is the Fundamental Assumption?
The fundamental assumption of Dummett’s and Prawitz’ prooftheoretic justification of deduction is that 'if we have a valid argument for a complex statement, we can construct a valid argument for it which finishes with an application of one of the introduction rules governing its principal operator'. I argue that the assumption is flawed in this general version, but should be restricted, not to apply to arguments in general, but only to proofs. I also argue that Dummett’s and Prawitz’ project of providing a logical basis for metaphysics only relies on the restricted assumption. Keywords: Prooftheoretic Semantics, Michael Dummett, Dag Prawitz, Verificationist Theories of Meaning, Realism vs. AntiRealism. Published in Teorema XXXI/2 (2012): 519 

Nils Kürbis: What is Interpretation? A Dilemma for Davidson
The core idea of Davidson’s philosophy of language is that a theory of truth constructed as an empirical theory by a radical interpreter is a theory of meaning. I discuss an ambiguity that arises from Davidson’s notion of interpretation: it can either be understood as the hypothetical process of constructing a theory of truth for a language or as a process that actually happens when speakers communicate. I argue that each disambiguation is problematic and does not result in a theory of meaning. Published in Conceptus 40(98) (2011): 5466 

Nils Kürbis: Stable Harmony
In this paper I give a formally precise definition of harmony and stability for Dummett's and Prawitz's prooftheoretic semantics. A short version of the paper below. Published in the Logica Yearbook 2008 

Nils Kürbis: Harmony, Normality and Stability
The paper begins with a conceptual discussion of Michael Dummett's prooftheoretic justification of deduction or prooftheoretic semantics, which is based on what we might call Gentzen's thesis: 'the introductions constitute, so to speak, the "definitions" of the symbols concerned, and the eliminations are in the end only consequences thereof, which could be expressed thus: In the elimination of a symbol, the formula in question, whose outer symbol it concerns, may only "be used as that which it means on the basis of the introduction of this symbol".' The intuitive philosophical content of Dummett's notions of harmony and stability is that harmony obtains if the grounds for asserting a proposition match the consequences of accepting it, and stability obtains if the converse also holds. Rules of inference define the meanings of a logical constant they govern if and only if they are stable. Gentzen observed that 'it should be possible to establish on the basis of certain requirements that the elimination rules are functions of the corresponding introduction rules.' One of the objectives of this paper is to specify such a function: I will specify a process by which it is possible to determine the elimination rules of logical constants from their introduction rules, and conversely, to determine the introduction rules from the elimination rules. I'll give the general forms of rules of inference and generalised reduction procedures for the normalisation of deduction. I'll give a formally precise characterisations of harmony and stability and show that deductions in logics that contain only constants governed by stable rules always normalise. Published exclusively here, by Nils Pumpkin Philosophy Publications! 
