University of Melbourne
School of Historical And Philosophical Studies
PhD, 2011
Irvine, California, United States of America
PhilPapers Editorships
Set Theory
  •  20
    Beyond Linguistic Interpretation in Theory Comparison
    Review of Symbolic Logic 1-41. forthcoming.
    This paper assembles a unifying framework encompassing a wide variety of mathematical instruments used to compare different theories. The main theme will be the idea that theory comparison techniques are most easily grasped and organized through the lens of category theory. The paper develops a table of different equivalence relations between theories and then answers many of the questions about how those equivalence relations are themselves related to each other. We show that Morita equivalence…Read more
  •  6
    Consistency, interpretability and probability are three key instruments in the mathematical philosopher’s kit when it comes to questions of foundational theory comparison. This paper aims to bring these tools together with a focus on theories capable of providing foundations for mathematics with a particular emphasis on set theory. A number of counterintuitive results emerge which are then addressed by offering a novel framework based on what we call pointwise interpretability. We then investiga…Read more
  •  40
    Forcing revisited
    Mathematical Logic Quarterly 69 (3): 287-340. 2023.
    The purpose of this paper is to propose and explore a general framework within which a wide variety of model construction techniques from contemporary set theory can be subsumed. Taking our inspiration from presheaf constructions in category theory and Boolean ultrapowers, we will show that generic extensions, ultrapowers, extenders and generic ultrapowers can be construed as examples of a single model construction technique. In particular, we will show that Łoś's theorem can be construed as a s…Read more
  •  23
    Relative Interpretation Between Logics
    Erkenntnis 88 (8): 3203-3220. 2021.
    Interpretation is commonly used in mathematical logic to compare different theories and identify cases where two theories are for almost all intents and purposes the same. Similar techniques are used in the comparison between alternative logics although the links between these approaches are not transparent. This paper generalizes theoretical comparison techniques to the case of logical comparison using an extremely general approach to semantics that provides a very generous playing field upon w…Read more
  •  22
    What is a Restrictive Theory?
    Review of Symbolic Logic 17 (1): 67-105. 2024.
    In providing a good foundation for mathematics, set theorists often aim to develop the strongest theories possible and avoid those theories that place undue restrictions on the capacity to possess strength. For example, adding a measurable cardinal to $ZFC$ is thought to give a stronger theory than adding $V=L$ and the latter is thought to be more restrictive than the former. The two main proponents of this style of account are Penelope Maddy and John Steel. In this paper, I’ll offer a third acc…Read more
  •  76
    Did Descartes make a Diagonal Argument?
    Journal of Philosophical Logic 51 (2): 219-247. 2021.
    This paper explores the idea that Descartes’ cogito is a kind of diagonal argument. Using tools from modal logic, it reviews some historical antecedents of this idea from Slezak and Boos and culminates in an orginal result classifying the exact structure of belief frames capable of supporting diagonal arguments and our reconstruction of the cogito.
  •  91
    Two arguments against the generic multiverse
    Review of Symbolic Logic 1-33. forthcoming.
    This paper critically examines two arguments against the generic multiverse, both of which are due to W. Hugh Woodin. Versions of the first argument have appeared a number of times in print, while the second argument is relatively novel. We shall investigate these arguments through the lens of two different attitudes one may take toward the methodology and metaphysics of set theory; and we shall observe that the impact of these arguments depends significantly on which of these attitudes is uphel…Read more
  •  99
    A reconstruction of steel’s multiverse project
    Bulletin of Symbolic Logic 26 (2): 118-169. 2020.
    This paper reconstructs Steel’s multiverse project in his ‘Gödel’s program’ (Steel [2014]), first by comparing it to those of Hamkins [2012] and Woodin [2011], then by detailed analysis what’s presented in Steel’s brief text. In particular, we reconstruct his notion of a ‘natural’ theory, describe his multiverse axioms and his translation function, and assess the resulting status of the Continuum Hypothesis. In the end, we reconceptualize the defect that Steel thinks CH might suffer from and is…Read more
  •  17
    Rigor and Structure, by John P. Burgess: Oxford: Oxford University Press, 2015, pp. xii + 215, £35 (review)
    Australasian Journal of Philosophy 95 (2): 397-400. 2017.
  •  82
    Unpicking Priest’s Bootstraps
    Thought: A Journal of Philosophy 4 (3): 181-188. 2015.
    Graham Priest has argued that the fruits of classical set theory can be obtained by naive means through a puzzling piece of reasoning often known as the bootstrapping argument. I will demonstrate that the bootstrapping involved is best understood as viciously circular and thus, that these fruits remain forbidden. The argument has only one rehearsal in print and it is quite subtle. This paper provides reconstruction of the argument based on Priest and attempts some fixes and alternative construal…Read more
  •  111
    An account of modality is produced which takes as its foundation the idea that modal concepts are parasitic upon our background theoretical commitments. This position is distinguished from the majority of philosophies of modality, which are either primitivist or reductionist. It is in this sense that our account is less burdened by metaphysics. The primary purpose of the document is to demonstrate that our approach is a coherent one. It supports this claim in three stages. First, we identify the…Read more
  •  106
    Revising Carnap’s Semantic Conception of Modality
    Studia Logica 100 (3): 497-515. 2012.
    I provide a tableau system and completeness proof for a revised version of Carnap's semantics for quantified modal logic. For Carnap, a sentence is possible if it is true in some first order model. However, in a similar fashion to second order logic, no sound and complete proof theory can be provided for this semantics. This factor contributed to the ultimate disappearance of Carnapian modal logic from contemporary philosophical discussion. The proof theory I discuss comes close to Carnap's sema…Read more
  •  107
    Computation in Non-Classical Foundations?
    with Zach Weber
    Philosophers' Imprint 16. 2016.
    The Church-Turing Thesis is widely regarded as true, because of evidence that there is only one genuine notion of computation. By contrast, there are nowadays many different formal logics, and different corresponding foundational frameworks. Which ones can deliver a theory of computability? This question sets up a difficult challenge: the meanings of basic mathematical terms are not stable across frameworks. While it is easy to compare what different frameworks say, it is not so easy to compare …Read more
  •  107
    WHAT CAN A CATEGORICITY THEOREM TELL US?
    Review of Symbolic Logic (3): 524-544. 2013.
    f The purpose of this paper is to investigate categoricity arguments conducted in second order logic and the philosophical conclusions that can be drawn from them. We provide a way of seeing this result, so to speak, through a first order lens divested of its second order garb. Our purpose is to draw into sharper relief exactly what is involved in this kind of categoricity proof and to highlight the fact that we should be reserved before drawing powerful philosophical conclusions from it
  •  41
    Naive Infinitism: The Case for an Inconsistency Approach to Infinite Collections
    Notre Dame Journal of Formal Logic 56 (1): 191-212. 2015.
    This paper expands upon a way in which we might rationally doubt that there are multiple sizes of infinity. The argument draws its inspiration from recent work in the philosophy of truth and philosophy of set theory. More specifically, elements of contextualist theories of truth and multiverse accounts of set theory are brought together in an effort to make sense of Cantor’s troubling theorem. The resultant theory provides an alternative philosophical perspective on the transfinite, but has limi…Read more
  •  121
    Sets and supersets
    Synthese 193 (6): 1875-1907. 2016.
    It is a commonplace of set theory to say that there is no set of all well-orderings nor a set of all sets. We are implored to accept this due to the threat of paradox and the ensuing descent into unintelligibility. In the absence of promising alternatives, we tend to take up a conservative stance and tow the line: there is no universe. In this paper, I am going to challenge this claim by taking seriously the idea that we can talk about the collection of all the sets and many more collections bey…Read more
  •  107
    Naive Infinitism: The Case for an Inconsistency Approach to Infinite Collections
    Notre Dame Journal of Formal Logic 56 (1): 191-212. 2015.
    This paper expands upon a way in which we might rationally doubt that there are multiple sizes of infinity. The argument draws its inspiration from recent work in the philosophy of truth and philosophy of set theory. More specifically, elements of contextualist theories of truth and multiverse accounts of set theory are brought together in an effort to make sense of Cantor’s troubling theorem. The resultant theory provides an alternative philosophical perspective on the transfinite, but has limi…Read more
  •  115
    Truth, Dependence and Supervaluation: Living with the Ghost
    Journal of Philosophical Logic 42 (2): 221-240. 2013.
    In J Philos Logic 34:155–192, 2005, Leitgeb provides a theory of truth which is based on a theory of semantic dependence. We argue here that the conceptual thrust of this approach provides us with the best way of dealing with semantic paradoxes in a manner that is acceptable to a classical logician. However, in investigating a problem that was raised at the end of J Philos Logic 34:155–192, 2005, we discover that something is missing from Leitgeb’s original definition. Moreover, we show that onc…Read more
  •  94
    Infinitary tableau for semantic truth
    Review of Symbolic Logic 8 (2): 207-235. 2015.