Bogdan is a philosopher and logician who, for the purposes of this website, acquired the disturbing habit of speaking of himself in the third person.

Currently, Bogdan is a postdoc at the University of Cagliari, where he works in the ALOPHIS research group.

Bogdan moved! As of September 2017, he's a postdoc at the Centre for Philosophy of the University of Lisbon.

Before becoming a humble proletarian, Bogdan obtained his PhD from the University of Melbourne with a thesis on logical pluralism written under the supervision of Greg Restall.

What the future will bring, no one knows.

Bogdan is also on twitter and instagram (though he forgot his password). Bogdan blogs here.

Here unfolds the tragedy of Bogdan's Nachgelassene. Each paper lost to the Nachgelassene gets listed here. A click on the titles below will open the abstract of the paper, the publication data and a link to a surprise pdf.

• A novel defence of meaning-invariant logical pluralism

  When: 2016

  Where: Mind (125(499):727-757; doi:10.1093/mind/fzv214)

  What about: In this paper I offer a proof-theoretic defence of meaning-invariant logical pluralism. I argue that there is a relation of co-determination between the operational and structural aspects of a logic. As a result, some features of the consequence relation are induced by the connectives. I propose that a connective is defined by those rules which are conservative and unique, while at the same time expressing only connective-induced structural information. This is the key to stabilizing the meaning of the connectives across multiple determinations of the consequence relation.

  Read it here.

• Weak disharmony: some lessons for proof-theoretic semantics

  When: 2016

  Where: The Review of Symbolic Logic (9(3):583-602; doi:10.1017/S1755020316000162)

  What about: A logical constant is weakly disharmonious if its elimination rules are weaker than its introduction rules. Substructural weak disharmony is the weak disharmony generated by structural restrictions on the eliminations. I argue that substructural weak disharmony is not a defect of the constants which exhibit it. To the extent that it is problematic, it calls into question the structural properties of the derivability relation. This prompts us to rethink the issue of controlling the structural properties of a logic by means of harmony. I argue that such a control is possible and desirable. Moreover, it is best achieved by global tests of harmony.

  Read it here.

• ST, LP, and tolerant metainferences (with Francesco Paoli)

  When: forthcoming

  Where: C. Baskent and T. Ferguson (eds.), Graham Priest on Dialetheism and Paraconsistency

  What about: The strict-tolerant (ST) approach to paradox promises to erect theories of naïve truth and tolerant vagueness on the safe bedrock of classical logic. We assess the extent to which this claim is founded. Building on some results by Girard [11], we show that the usual proof-theoretic formulation of propositional ST in terms of the classical sequent calculus without primitive Cut is incomplete with respect to ST-valid metainferences, and exhibit a complete calculus for the same class of metainferences. We also argue that the latter calculus, far from coinciding with classical logic, is a close kin of Priest’s LP.

  Read a drafthere.

• On a generality condition in proof-theoretic semantics

  When: 2017

  Where: Theoria

  What about: Recently, Nissim Francez defended a generality condition on defining rules in proof-theoretic semantics, according to which the schematic formulation of the defining rules must be maximally general. (See his wonderful book, Proof-theoretic semantics.) Context variables must always be present in the schematic rules and they should range over arbitrary collections of formulae. Moreover, no restrictions must be placed on the contexts of these rules. I argue against imposing such a condition.

  Read it here

• Hopeful monsters: A note on multiple conclusions

  When: forthcoming 2018

  Where: Erkenntnis

  What about: Arguments are usually understood as having one or more premises and only one conclusion. However, this notion of argument can be generalised and we may let arguments have not one, but several disjunctively connected conclusions. This is a contentious generalisation. In this paper I will argue that it is, nonetheless, justified. I argue that multiple conclusions are epiphenomena of the logical connectives. That is, I argue that some connectives induces multiple-conclusion derivations. In this sense, such derivations are completely natural. Moreover, I argue that they can safely be used in the proof-theoretic semantics.

  Read it here.

• Variations on intra-theoretical logical pluralism: Internal vs. external consequence

  When: forthcoming 2018

  Where: Philosophical Studies

  What about: Intra-theoretical logical pluralism is a form of meaning-invariant pluralism about logic, articulated recently by Hjortland (2013). This version of pluralism relies on it being possible to define several distinct notions of provability relative to the same logical calculus. The present paper picks up and explores this theme: How can a single logical calculus express several different consequence relations? The main hypothesis articulated here is that the divide between the internal and external consequence relations in Gentzen systems generates a form of intra-theoretical logical pluralism.

  Read it here.

• The original sin of proof-theoretic semantics (with Francesco Paoli)

  When: forthcoming

  Where: Synthese

  What about: Proof-theoretic semantics is an alternative to model-theoretic seman- tics. It aims at explaining the meaning of the logical constants in terms of the inference rules that govern their behaviour in proofs. We argue that this must be construed as the task of explaining these meanings relative to a logic, i.e., to a consequence relation. Alas, there is no agreed set of properties that a relation must have in order to qualify as a consequence relation. Moreover, the association of a consequence relation to a logical calculus is not as straightforward as it may seem. We show that these facts are problematic for the proof-theoretic project but the problems can be solved. Our thesis is that the consequence relation relevant for proof- theoretic semantics is the one given be the sequent-to-sequent derivability relation in Gentzen systems.

  Read it here.

• Cut for bilateralist intuitionists

  When: forthcoming

  Where: Analysis

  What about: On a bilateralist reading, sequents are interpreted as statements to the effect that, given the assertion of the antecedent it is incoherent to deny the succedent. This interpretation goes against its own ecumenical ambitions, endowing Cut with a meaning very close to that of tertium non datur and thus rendering it intuitionistically unpalatable. This paper explores a top-down route for arguing that, even intuitionistically, a prohibition to deny is as strong as a license to assert. (Note: The official title of the paper is 'Ask not what bilateralist intuitionists can do for Cut, but what Cut can do for bilateralist intuitionism'.)

  Read it here.

Bogdan is a bit more reluctant when it comes to sharing drafts. So, until he gathers up his courage, here are the tentative titles and abstracts of the draft papers. If you really want them, drop him an email saying so.

• On logical nihilism

  In which I argue against logical nihilism understood as the claim that the logical consequence relation is empty.

• A defence of Belnapian harmony

  Dummett identified harmony with conservativeness, which, as you recall, was half of Belnap's solution to tonk. The other half is uniqueness. Conservativeness is tricky. It is a global property of proof systems and it seems wrong to take it as the formal mark of a local property of introduction-elimination rules. In this paper I argue that this shouldn't be a worry. Indeed, Belnap's dual criterion of definitional success is the best formal expression of harmony.

• That paper on Finnis on gay marriage that still needs a title

  Reshaping the ideas of a plump Italian monk from the Middle Ages into the basis of sexual morality in the 21st century is a stroke of genius. Of course, it doesn't work. In this paper I try to show that it doesn't work in the particular case of gay marriage. Now, this has been done quite a number of times. (It looks easy enough, right?) Well, here I'm trying to put myself into Finnis' shoes and show that it doesn't work by his own lights. Lights out (not literally!) and get on to it, however you like it! We need link, don't we? It's here.

• Meaning, rules, and proofs

  This year Bogdan is teaching a doctoral course on proof-theoretic semantics and some other stuff. It's fun. He has one formal student, so he feels a bit like Frege. Fortunately, there's no reason for him to feel like Violetta (you know, solo, abbandonato in questo popoloso deserto and so on and so forth). That's because he has a wider audience consisting of other students, colleagues, and supra-colleagues (i.e., the boss, Francesco Paoli). Click here for the syllabus.

How do you feel about the musical version of it? Click here. Well, Bogdan may have exagerated when doctoring it: for one thing, he can't whistle. (Oh, you don't like opera? In that case, you get exclusive access to Bogdan's personal playlist.)

The short version is here.

The technical aspects. This site is made with Hugo and hosted on GitHub - so Bogdan borrowed Rohan's idea of stealing consequently's idea. Using Hugo was quite unnecessary: Bogdan soon realised that he needs to write a theme. For that, he'd have had to understand the syntax of Go. But his procrastination needs are nowhere near so complex. So, he went over to codrops, lawfully appropriated this template, and cheerfully (and mercilessly) hacked the css and html provided. By Paris, you should enjoy the result: the colour scheme of the previous live version was inspired by the rainbow lorikeet.

The grand perspective. It's grand but simple and elaborated by John Perry. Bogdan had bucketloads of work to do, so he decided to revive his website.