A collection of nearly 50 original chapters addressing the mental lives of animals. Covered topics include: whether and how animals represent and reason about the world; how animal cognition differs from human cognition; whether animals are conscious; whether animals represent their own mental states or those of others; how animals communicate; the extent to which animals have cultures; how to choose among competing models and explanations of animal behavior; and whether animals are moral agents and/or moral patients.
Relationalism maintains that mind-independent objects are essential constituents of veridical perceptual experiences. According to the argument from hallucination, relationalism is undermined by perfect hallucinations, experiences that are introspectively indistinguishable from veridical perceptual experiences but lack an object. Recently, a new wave of relationalists have responded by questioning whether perfect hallucinations are possible: what seem to be perfect hallucinations may really be something else, such as illusions, veridical experiences of non-obvious objects, or experiences that are not genuinely possible. This paper argues that however well new wave relationalism may handle brains in vats, drug users “seeing” pink elephants, and other extraordinary hallucinations, it struggles to accommodate mundane hallucinations, such as “hearing” your child cry out from the room down the hall when she is actually sound asleep or “feeling” vibrations on your thigh even when your phone isn’t in your pocket. Mundane hallucinations are best explained as byproducts of noise in the perceptual system, and noise-induced hallucinations are resistant to the strategies that new wave relationalists deploy to explain away other hallucinations. Mundane hallucinations can thus underpin an especially powerful version of the argument from hallucination.
Numbers, Numerosities, and New Directions (w/ Sam Clarke)
Behavioral and Brain Sciences, 2021
This is our reply to the peer commentaries to our target article, “The Number Sense Represents Rational Numbers.”
In our target article, we argued that the number sense represents natural and rational numbers. Here, we respond to the 26 commentaries we received, highlighting new directions for empirical and theoretical research. We discuss two background assumptions, arguments against the number sense, whether the approximate number system (ANS) represents numbers or numerosities, and why the ANS represents rational (but not irrational) numbers.
The Number Sense Represents (Rational) Numbers (w/ Sam Clarke)
Behavioral and Brain Sciences, 2021
This target article was published alongside 26 peer commentaries and our reply.
On a now orthodox view, humans and many other animals possess a “number sense,” or approximate number system (ANS), that represents number. Recently, this orthodox view has been subject to numerous critiques that question whether the ANS genuinely represents number. We distinguish three lines of critique—the arguments from congruency, confounds, and imprecision—and show that none succeed. We then provide positive reasons to think that the ANS genuinely represents numbers, and not just non-numerical confounds or exotic substitutes for number, such as “numerosities” or “quanticals,” as critics propose. In so doing, we raise a neglected question: numbers of what kind? Proponents of the orthodox view have been remarkably coy on this issue. But this is unsatisfactory since the predictions of the orthodox view, including the situations in which the ANS is expected to succeed or fail, turn on the kind(s) of number being represented. In response, we propose that the ANS represents not only natural numbers (e.g. 7), but also non-natural rational numbers (e.g. 3.5). It does not represent irrational numbers (e.g. √2), however, and thereby fails to represent the real numbers more generally. This distances our proposal from existing conjectures, refines our understanding of the ANS, and paves the way for future research.
John Morrison has argued that confidences are assigned in perceptual experience. For example, when you perceive a figure in the distance, your experience might assign a 55-percent confidence to the figure’s being Isaac. Morrison’s argument leans on the phenomenon of ‘completely trusting your experience’. I argue that Morrison presupposes a problematic ‘importation model’ of this familiar phenomenon, and propose a very different way of thinking about it. At issue are not only whether confidences are assigned in perceptual experience, but also, and more generally, how we can determine which properties are assigned in perceptual experience, and how we should understand transitions from perception to belief.
Perception Is Analog: The Argument from Weber’s Law
The Journal of Philosophy, 2019
An early version of this paper was co-winner of the 2017 Antwerp Centre for Philosophical Psychology Essay Prize
In the 1980s, a number of philosophers argued that perception is analog. In the ensuing years, these arguments were forcefully criticized, leaving the thesis in doubt. This paper draws on Weber’s Law, a well-entrenched finding from psychophysics, to advance a new argument that perception is analog. This new argument is an adaptation of an argument that cognitive scientists have leveraged in support of the contention that primitive numerical representations are analog. But the argument here is extended to the representation of non-numerical magnitudes, such as luminance and distance, and shown to apply to perception and not just cognition. The relevant sense of ‘analog’ is also clarified, and two powerful objections are addressed. Finally, the question whether perception’s analog vehicles are located in conscious experience is explored and related to a well-known controversy within psychophysics.
Over the past 50 years, philosophers and psychologists have perennially argued for the existence of analog mental representations of one type or another. This study critically reviews a number of these arguments as they pertain to three different types of mental representation: perceptual representations, imagery representations, and numerosity representations. Along the way, careful consideration is given to the meaning of “analog” presupposed by these arguments, and to open avenues for future research.
Marking the Perception–Cognition Boundary: The Criterion of Stimulus-Dependence
Australasian Journal of Philosophy, 2018
Philosophy, scientific psychology, and common sense all distinguish perception from cognition. While there is little agreement about how the perception–cognition boundary ought to be drawn, one prominent idea is that perceptual states are dependent on a stimulus, or stimulus-dependent, in a way that cognitive states are not. This paper seeks to develop this idea in a way that can accommodate two apparent counterexamples: hallucinations, which are prima facie perceptual yet stimulus-independent; and demonstrative thoughts, which are prima facie cognitive yet stimulus-dependent. The payoff is not only a specific proposal for marking the perception–cognition boundary, but also a deeper understanding of the natures of hallucination and demonstrative thought.
Drawing on the empirical premise that attention makes objects look more intense (bigger, faster, higher in contrast), Ned Block has argued for mental paint, a phenomenal residue that cannot be reduced to what is perceived or represented. If sound, Block’s argument would undermine direct realism and representationism, two widely held views about the nature of conscious perception. We argue that Block’s argument fails because the empirical premise it is based upon is false. Attending to an object alters its salience, but not its perceived intensity. We also argue that salience should be equated with mental primer, a close cousin of mental paint that reintroduces difficulties for direct realism and representationism. The upshot is that direct realism and representationism are still in trouble, but not for the reason that Block thinks.
Here is a popular writeup summarizing the gist of the article.
Do Nonhuman Animals Have a Language of Thought?
Routledge Handbook of Philosophy of Animal Minds, 2017
Analogue Magnitude Representations: A Philosophical Introduction
British Journal for the Philosophy of Science, 2015
Sense, Mentalese, and Ontology
Protosociology, 30: Concepts: Contemporary & Historical Perspectives, 2013
Shorter Academic Pieces
Some Worries about the ‘No-Overflow’ Interpretation of Post- Stimulus Cueing Experiments
Mind & Language Symposium at the Brains Blog, June 12, 2017
I comment on Steven Gross and Jonathan Flombaum’s article, “Does Perceptual Consciousness Overflow Cognitive Access? The Challenge from Probabilistic, Hierarchical Processes.” Be sure to also see Robert Briscoe’s general overview, Nico Orlandi and Aaron Franklin’s commentary, Ian Phillips’ commentary, and Gross and Flombaum’s replies.
Reflecting on the life of Sarah, a chimpanzee who served as a research subject for most of her life, I argue that our ability to understand animal thought is subject to principled limitations.
Translated into French for La Conversation: Peut-on réellement savoir à quoi pensent les animaux?
Translated into Arabic for Popular Science Arabia: هل من الممكن أن تفكّر الحيوانات كما نفكّر حقاً؟
My live radio interview about this piece on the Jill Bennett Show (starting around 17:10)
The Only Good Reason to Ban Steroids in Baseball: To Prevent an Arms Race
The Atlantic, June 17, 2013