Explaining Consciousness-Foundational and Methodological Issues in the Philosophical Investigation of Conscious Experience

解释性间隙理论（GAP）声称认知科学无法解释为什么神经活动会产生主观意识状态，如疼痛和视觉感觉（Levine 2006，查尔默斯2009）。GAP的支持者认为，这种“解释性空白”是独一无二的，因为其他形而上学问题没有类似的解释性空白，比如为什么粒子的排列会产生普通的物质对象。然而，GAP似乎假定神经状态是否产生意识是一个实质性（非概念性）问题，而显然将其他有争议的形而上学问题仅仅视为概念性问题，以避免出现许多平行的解释空白（Schaffer 2017）。因此，GAP的支持者似乎“缩小”了大多数形而上学问题，同时“膨胀”了那些与意识有关的问题，从而对形而上学问题的实质性做出了特别的假设。这一论证思路开启了GAP与形而上学之间的新的联系，即对形而上学的意义和方法论的探讨。这些联系是否存在以及如何理解它们将是我博士论文的主要主题。理解解释缺口的性质对于回答意识的形而上学问题以及根据潜在的物理过程解释意识状态的可能性至关重要。这个项目将研究GAP背后的形而上学假设。它将主要集中在解释差距的辩论和形而上学问题是否是实质性的（“通货膨胀论”），而不仅仅是概念性的（“通货紧缩论”）之间的未探索的联系。首要的目的是要证明，GAP不依赖于特设的形而上学假设，因此，解释的差距不仅仅是一个狭隘的方法形而上学的副产品。该项目将做出三个主要贡献：（1）确定当前的GAP公式（特别是查尔默斯2009和Levine 2006）是否依赖于特设的形而上学假设。(2)证明，尽管“膨胀”大多数形而上学问题（通过将它们视为实质性问题）会在所有地方产生解释缺口，但这些缺口与神经状态和意识之间的解释缺口有着重要的不同。(3)说明缩小神经状态是否产生意识的问题（通过将其归类为仅仅是概念性的）不会破坏GAP。该项目将弥合当代哲学中两个突出的争论（一个关于意识，一个关于形而上学问题的实体性），其联系在很大程度上未被探索，从而为一个持久的哲学问题提供了一种新的方法。关于解释差距的性质缺乏共识：一些人声称它在形而上学和科学上是无关紧要的（Dennett 2016，Frankish 2016），而另一些人则认为它的存在挑战了自然主义，并呼吁对认知科学进行彻底的修订（查尔默斯2009，Levine 2018）。这表明，解释缺口的性质问题是至关重要的，并触及心灵哲学和认知科学之间的关系。通过澄清GAP，该项目也可以有助于阐明理论和经验方法之间的关系。

The explanatory gap thesis (GAP) claims that cognitive science cannot explain why neural activity gives rise to subjective conscious states, such as pain and visual sensations (Levine 2006, Chalmers 2009). Proponents of GAP argue that this "explanatory gap" is unique, as there are no parallel explanatory gaps attaching to other metaphysical questions, such as why arrangements of particles give rise to ordinary material objects. However, GAP seems to presuppose that it is a substantive (non-conceptual) question whether neural states give rise to consciousness, while apparently treating other contested metaphysical questions as merely conceptual, to avoid the emergence of many parallel explanatory gaps (Schaffer 2017). Thus, proponents of GAP appear to "deflate" the majority of metaphysical questions, while simultaneously "inflating" those concerning consciousness, thereby making ad hoc assumptions about the substantiality of metaphysical questions. This line of argument opens up new connections between GAP and metametaphysics, i.e. the inquiry into the significance and methodology of metaphysics. Whether these connections exist and how they are to be understood will be the main topic of my doctoral thesis. Understanding the nature of the explanatory gap is crucial to answering questions about the metaphysics of consciousness and the possibility of explaining conscious states in terms of the underlying physical processes. This project will examine the metametaphysical assumptions underlying GAP. It will focus primarily on the unexplored connections between debates on the explanatory gap and debates on whether metaphysical questions are substantive ("inflationism"), as opposed to merely conceptual ("deflationism"). The overarching aim is to demonstrate that GAP does not rely on ad hoc metametaphysical assumptions and, hence, that the explanatory gap is not the mere by-product of a parochial approach to metaphysics. The project will make three main contributions: (1) Determine whether current formulations of GAP (especially Chalmers 2009 and Levine 2006) rely on ad hoc metametaphysical assumptions. (2) Demonstrate that, although "inflating" most metaphysical questions (by considering them to be substantive) would create explanatory gaps all over, these gaps would be importantly different from the explanatory gap between neural states and consciousness. (3) Illustrate how deflating the question of whether neural states give rise to consciousness (by classifying it as merely conceptual) would not undermine GAP. This project will bridge two prominent debates in contemporary philosophy (one concerning consciousness and one concerning the substantiality of metaphysical questions) whose connections are largely unexplored, thereby presenting a new approach to an enduring philosophical problem. Consensus is lacking regarding the nature of the explanatory gap: some claim it is metaphysically and scientifically inconsequential (Dennett 2016, Frankish 2016), while others hold that its existence challenges naturalism and calls for radical revisions in cognitive science (Chalmers 2009, Levine 2018). This shows that the issue of the nature of the explanatory gap is crucial, and touches upon the very relation between the philosophy of mind and cognitive science. By clarifying GAP, the project could thus also contribute to illuminating the relation between theoretical and empirical approaches to the mind.