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I'm a post-doc in the Logic of Conceivability project at the Institute for Logic, Language and Computation at the University of Amsterdam. I defended my Ph.D in January 2017 at the 
Stanford department of philosophyMy advisors were Johan van Benthem and Krista Lawlor.

I work on epistemology, logic and connected issues concerning mind, language and rationality. My research explores the interaction between knowledge, meaning and modality. MGoogle Scholar Page.

I'm from South Africa. I studied mathematics and, later, philosophy at the University of the Witwatersrand.

Reach me at: p DOT m DOT hawke AT uva DOT nl


Knowledge and Knowability

Questions, Topics and Restricted Closure in Philosophical Studies

Abstract I argue that the denial of epistemic closure is a respectable position so long as one defends a restricted closure principle that meets certain constraints. I evaluate both Schaffer's proposal that knowability is question-sensitive and Yablo's proposal that knowability is topic-sensitive, understood as forms of restricted closure endorsement. After casting doubt on these approaches, I present a novel theory that fares better: resolution theory.

Epistemology of Modality

Van Inwagen’s Modal Skepticism in Philosophical Studies

Abstract A moderate modal skeptic thinks that mundane possibility claims tend to be justified, but that exotic possibility claims of special philosophical interest tend to be unjustified. Van Inwagen arrives at this view by arguing that possibility is established by conceivability, but the conceivability at issue is relatively demanding. I defend his view from a seeming dilemma: if the account of conceivability is strict, then mundane possibilities cannot be established; if the account is liberal, then exotic possibilities can be established. The reply drives the moderate modal skeptic toward modal empiricism. 

Can Modal Skepticism Defeat Humean Skepticism? in Modal Epistemology After Rationalismeds. R. W. Fischer and F. Leon 

Abstract I present and defend a novel reply to Humean skepticism based on modal empiricism/skepticism: given ordinary evidence, it is reasonable to believe that green emeralds are really possible but not reasonable to believe that non-green emeralds are really possible and, what's more, what one reasonably believes is a function only of those alternatives that one reasonably believes to be real possibilities. The paper amounts to an abductive argument in defense of modal empiricism: modal empiricism provides tools for resolving an otherwise intractable philosophical paradox.

Modal Discourse


Abstract In the spirit of expressivism (broadly construed), we present a precise theory of the role of 'might' claims in ordinary discourse: a 'might' claim expresses lack of belief in a certain proposition, and acceptance of a might claim is to update one's doxastic state so as to ensure that one lacks the requisite belief. We prove a theorem linking an arbitrary assertion (possibly composed of both 'might' and simple declarative sentences) to a well-defined mental state, and investigate the properties of a novel doxastic update operation connected to our proposal.

Strategic Ability and Information


Abstract I consider joint ability in the context of a tacit game: a game where the cooperating agents cannot communicate, and so coordination of action becomes a challenge. I offer and investigate a novel variant of coalition logic that includes an ability modality for capturing what coalitions can enforce in tacit play.

Markov Operators On Banach Lattices

Markov Operators on Banach Lattices M.Sc Dissertation, University of the Witwatersrand, Johannesburg. 
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