Andrew Y. Lee

Are some creatures “more conscious” than others? A number of consciousness researchers have aimed to answer this question. Yet some have claimed that this question doesn’t even make sense. They claim that ‘conscious’ (in the phenomenal sense) never occurs as a gradable adjective, meaning an adjective that permits degree expressions (‘more F than’, ‘slightly F’, etc.) and that’s associated with a degreed property. Both sides face an explanatory burden: they must explain why some competent speakers seem confused about the meaning of ‘conscious’. We argue that the question does make sense: ‘conscious’ sometimes functions as a minimal-standard gradable adjective. But we will also explain why some theorists have been skeptical about gradable uses of ‘conscious’. Along the way, we address the objection that many gradable constructions involving ‘what it’s like’ expressions are infelicitous, distinguish two interpretations of ‘phenomenal consciousness’, and discuss how our semantic arguments bear on the metaphysical question of whether consciousness comes in degrees.

I develop and defend a sense-datum theory of perception. My theory follows the spirit of classic sense-datum theories: I argue that what it is to have a perceptual experience is to be acquainted with some sense-data, where sense-data are private particulars that have all the properties they appear to have, that are common to both perception and hallucination, that constitute the phenomenal characters of perceptual experiences, and that are analogous to pictures inside one’s head. But my theory also diverges from conventional sense-datum theories in some key respects: on my view, (1) sense-data are first-person presentations of neural states, (2) the sensational qualities of sense-data differ in kind from the sensible qualities of external objects, and (3) sense-data are the vehicles in virtue of which we perceive, rather than the objects that we perceive. I argue that this package of claims is appropriately labeled ‘sense-datum theory’, and that the resultant view ought to be a live contender in contemporary philosophy of perception.

A famous mathematical theorem says that the sum of an infinite series of numbers can depend on the order in which those numbers occur. Suppose we interpret the numbers in such a series as representing instances of some physical quantity, such as the weights of a collection of items. The mathematics seems to lead to the result that the weight of a collection of items can depend on the order in which those items are weighed. But that is very hard to believe. A puzzle then arises: How do we interpret the metaphysical significance of this mathematical theorem? I first argue that prior solutions to the puzzle lead to implausible consequences. Then I develop my own solution, where the basic idea is that the weight of a collection of items is equal to the limit of the weights of its finite subcollections contained within ever-expanding regions of space. I show how my solution is intuitively plausible and philosophically motivated, how it reveals an underexplored line of metaphysical inquiry about quantities and locations, and how it elucidates some classic puzzles concerning supertasks.

I develop and defend "metaethical experientialism," the thesis that phenomenal facts explain certain kinds of value facts. I argue, for example, that anyone who knows what it’s like to feel extreme pain is in a position to know that that kind of experience is bad. I argue that metaethical experientialism yields genuine counterexamples to the principle that no ethical conclusion can be derived from purely descriptive premises. I also discuss the prospects for a pluralistic metaethics, whereby different metaethical theories hold for different classes of ethical facts.

This paper argues that knowledge of what it’s like varies along a spectrum from more exact to more approximate, and that phenomenal concepts vary along a spectrum in how precisely they characterize what it’s like to undergo their target experiences. This degreed picture contrasts with the standard all-or-nothing picture, where phenomenal concepts and phenomenal knowledge lack any such degreed structure. I motivate the degreed picture by appeal to (1) limits in epistemic abilities such as recognition, imagination, and inference, and (2) the semantics of ‘knows what it’s like’ expressions. I argue that approximate phenomenal knowledge cannot be explained merely via determinable or vague phenomenal concepts. I develop a framework for systematizing approximate knowledge of phenomenal character. And I explain how my view challenges some standard assumptions about the acquisition conditions, requirements for mastery, and referential mechanisms of phenomenal concepts.

This paper develops a theory of analog representation. We first argue that the mark of the analog is to be found in the nature of a representational system’s interpretation function, rather than in its vehicles or contents alone. We then develop the rulebound structure theory of analog representation, according to which analog systems are those that use interpretive rules to map syntactic structural features onto semantic structural features. The theory involves three degree-theoretic measures that capture three independent ways in which a system can be more or less analog. We explain how our theory improves upon prior accounts of analog representation, provides plausible diagnoses for novel challenge cases, extends to hybrid systems that are partially analog and partially symbolic, and accounts for some of the advantages and disadvantages of representing analogically versus symbolically.

This paper examines the idea of "objective phenomenology," or a way of understanding the phenomenal character of conscious experiences that doesn’t require one to have had the kinds of experiences under consideration. My central thesis is that structural facts about experience—facts that characterize purely how conscious experiences are structured—are objective phenomenal facts. I begin by precisifying the idea of objective phenomenology and diagnosing what makes any given phenomenal fact subjective. Then I defend the view that structural facts about experience are objective. I also argue that structural facts about experience, despite being objective, nevertheless still give rise to an explanatory gap.

In the science of consciousness, it’s oftentimes assumed that some creatures (or mental states) are more conscious than others. But in recent years, a number of philosophers have argued that the notion of degrees of consciousness is conceptually confused. This paper (1) argues that the most prominent objections to degrees of consciousness are unsustainable, (2) examines the semantics of ‘more conscious than’ expressions, (3) develops an analysis of what it is for a degreed property to count as degrees of consciousness, and (4) applies the analysis to various theories of consciousness. I argue that whether consciousness comes in degrees ultimately depends on which theory of consciousness turns out to be correct. But I also argue that most theories of consciousness entail that consciousness comes in degrees.

Many philosophers accept both of the following claims: (1) consciousness matters morally, and (2) species membership doesn’t matter morally. In other words, many reject speciesism but accept what we might call 'sentientism'. But do the reasons against speciesism yield analogous reasons against sentientism, just as the reasons against racism and sexism are thought to yield analogous reasons against speciesism? This paper argues that speciesism is disanalogous to sentientism (as well as racism and sexism). I make a case for the following asymmetry: (a) some non-humans clearly have interests, but (b) no non-conscious entities clearly have interests. This asymmetry, I argue, renders sentientism resistant to the standard argument against speciesism.

There are some things that we think are intrinsically valuable, or valuable for their own sake. Is consciousness—subjective, qualitative experience—one of those things? Some theorists favor the positive view, according to which consciousness is intrinsically valuable. According to a positive theorist, consciousness itself accrues intrinsic value, independent of the particular kind of experience instantiated. In contrast, I favor the neutral view, according to which consciousness is neither intrinsically valuable nor disvaluable. The primary purpose of this paper is to clarify what is at stake when we ask whether consciousness is intrinsically valuable, to carve out the theoretical space, and to evaluate the question rigorously. The secondary purpose is to show why the neutral view is attractive and why certain arguments for the positive view do not work.

Conscious experiences are characterized by mental qualities, such as those involved in seeing red, feeling pain, or smelling cinnamon. The standard framework for modeling mental qualities represents them via points in geometrical spaces, where distances between points inversely correspond to degrees of phenomenal similarity. This paper argues that the standard framework is structurally inadequate and develops a new framework that is more powerful and flexible. The core problem for the standard framework is that it cannot capture precision structure: for example, consider the phenomenal contrast between seeing an object as crimson in foveal vision versus merely as red in peripheral vision. The solution I favor is to model mental qualities using regions, rather than points. I explain how this seemingly simple formal innovation not only provides a natural way of modeling precision, but also yields a variety of further theoretical fruits: it enables us to formulate novel hypotheses about the space and structures of mental qualities, formally differentiate two dimensions of phenomenal similarity, generate a quantitative model of the phenomenal sorites, and define a measure of discriminatory grain. A noteworthy consequence is that the structure of the mental qualities of conscious experiences is fundamentally different from the structure of the perceptible qualities of external objects.