Swamp Mary Semantics: A Case for Physicalism Without Gaps


Welcome to my weird adventure.


Here begins the first post in the serialization of my work in progress, “Swamp Mary Semantics: A Case for Physicalism Without Gaps,” sequel to “Swamp Mary’s Revenge: Deviant Phenomenal Knowledge and Physicalism,” forthcoming in Philosophical Studies.


            I argue for the superiority of non-gappy physicalism over gappy physicalism. While physicalists are united in denying an ontological gap between the phenomenal and the physical, the gappy affirm and the non-gappy deny a relevant epistemological gap. Central to my arguments will be contemplation of Swamp Mary, a being physically intrinsically similar to post-release Mary (a physically omniscient being who has experienced red) but has not herself (the Swamp being) experienced red. Swamp Mary has phenomenal knowledge of a phenomenal character not instantiated by any of her past or current mental states. I issue a challenge to gappy physicalists to account for how it is that Swamp Mary can satisfy the psychosemantic requirements on phenomenal knowledge while non-Swamp pre-release Mary cannot. I argue that gappy physicalists cannot meet this psychosemantic challenge.

1. Introduction

            Physicalism is under threat, so the story goes, from an epistemic gap that exists between physical facts and phenomenal facts (Chalmers, 2003). Many qualia-based antiphysicalisms are based on inferring an ontological gap from the epistemic gap, the latter gap variously characterized in terms of what can be known, conceived, or explained. For example, in the famous argument concerning colorblind super-neuroscientist Mary (Jackson, 1982), it is inferred that physical facts cannot exhaust the totality of facts since Mary may be physically omniscient without thereby knowing what it is like to see red.

            One line of physicalist defense, a line that it will be the main aim of the present paper to criticize, involves embracing the epistemic gap while denying the ontological gap. I shall call such physicalists gappy physicalists. One of the most prominent versions of gappy physicalism is what has been referred to as the phenomenal concept strategy (Stoljar, 2005). Advocates of this strategy include Loar (1990), Balog (forthcoming), Block (2006), Papineau (2002; 2007), Tye (2000), and Perry (2001). The gist of what phenomenal concepts are supposed to be may be conveyed in terms of Mary: what she learns upon learning what it is like to see red is constituted by the acquisition of a new concept that puts her in a position to conceive of old facts in a new way. The epistemic gap thus opens up because of a gap between two different kinds of concept, phenomenal concepts and physical concepts, not a gap between two kinds of properties or two kinds of facts.

            Not all gappy physicalists are advocates of the phenomenal concept strategy. For example, Prinz’s (2007) “mental pointing” account postulates non-conceptual phenomenal demonstratives to account for the gap between Mary’s  pre- and post-release knowledge. Tye (2009), having terminated his allegiance to the phenomenal concepts strategy, nonetheless attempts to maintain allegiance to gappy physicalism via the postulation of physicalistically respectable version of knowledge by acquaintance. What unites gappy physicalists (besides, of course, their physicalism) is their holding that phenomenal knowledge is a kind of factual knowledge distinguished from physical knowledge not by what facts it is knowledge of but in how certain physical facts are represented.

A physicalist thesis hinging on how certain facts are represented incurs an obligation to, if not give a physicalistic explanation of representation, at least not violate physicalistic requirements on what representation can be. The purpose of the present paper is to articulate a criticism that applies to all gappy physicalists by calling into question their ability to satisfy physicalist psychosemantic strictures on phenomenal knowledge.

Central to my criticism will be drawing certain consequences of the Swamp Mary thought experiment (Alter, 2008; Dennett, 2005; P. Mandik, in press). Key features of Swamp Mary are that (1) she is intrinsically physically identical to post-release Mary, (2) she knows what it’s like to see (hallucinate, afterimage, etc.) red, and (3) she has sprung into being without herself ever having had a mental state with a red quale. The core consequence of the Swamp Mary thought experiment that I will draw is that gappy physicalists cannot account for how it is that Swamp Mary does, while pre-release Mary does not, satisfy the psychosemantic criteria for knowing what it’s like to see red. In previous work (Mandik, in press) I develop a case against antiphysicalism based on psychosemantic asymmetries between pre-release Mary and Swamp Mary. I will not recount those arguments here and instead proceed by assuming physicalism and developing a critique of gappy physicalism.

            The structure of the remainder of the paper is as follows. In §2, I lay out further preliminaries, including further relevant details of gappy physicalism and the Swamp Mary scenario. In §3, I discuss the broad outlines of various physicalistic theories of content that might possibly underwrite the psychosemantic requirements on phenomenal knowledge. I then spell out how gappy physicalists are incapable of rising to the psychosemantic challenge of explaining how it is that Swamp Mary can represent the phenomenal facts as phenomenal without it also being the case that pre-release Mary can do so as well. In §4 I spell out a suggestion that physicalists abandon attempts to explain an epistemic gap (there being none) and devote their energies instead to explaining why there ever appeared to be an epistemic gap in the first place. I also present some speculations as how such explanations might best proceed.



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3 Responses to “Swamp Mary Semantics: A Case for Physicalism Without Gaps”

  1. Eric Thomson says:

    Sounds very cool! Swamp Mary I consider a real advance in phil of consciousness, perhaps the first major advance in all these back and forths between qualia freaks and phobes since I left philosophy.

  2. Pete Mandik says:

    Thanks, Eric. I hope you’re right that this can help move things forward.

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