John Morrison


I am professor and chair of philosophy and director of cognitive science at Barnard College, Columbia University. I am an affiliate of Barnard's Neuroscience and Behavior Department, Columbia's Mind Brain Behavior Institute, and Columbia's Center for Theoretical Neuroscience. I am also a mentor in Columbia's Neurobiology and Behavior Graduate Program. I am an editor of the Journal of Philosophy.


My research is primarily in the philosophy of mind and the history of modern philosophy (esp. the seventeenth century). I also have strong secondary interests in metaphysics, medieval philosophy, and the philosophy of language.

I am currently working on two projects. The first is an attempt to understand the brain from an abstract perspective. Physics and economics provide helpful models of what I'm aiming for. When trying to understand a thermodynamic system, it’s often better to abstract away from the activities of individual molecules, and instead focus on more global features, such as pressure and temperature. When trying to understand an economic system, it’s often better to abstract away from the activities of individual consumers, and instead focus on more global features, such as inflation and gross domestic product. Likewise, when trying to understand brains, it’s often useful to abstract away from activities of individual neurons, and instead focus on more global features, such as representation and inference. This is particularly true when trying to understand how our brains enable us to successfully interact with our environment. Unfortunately, whereas we have precise and uniform definitions of pressure, temperature, inflation, and gross domestic product, there are no widely accepted definitions of representation and inference. Perhaps as a result, it is far less clear how to map representations and inferences onto brain activity. It is also far less clear what neuroscientists mean when they use these terms, because they often use them in loose and contradictory ways. The overall goal of this project is to develop a useful and precise framework for attributing representations and inferences to the brain, especially when they involve probabilities.

This project builds on past research on conscious perception. In one line of research, I argued that our conscious perceptions involve probabilities. I called this view Perceptual Confidence. I am now expanding my focus to include unconscious neural representations and the probabilistic inferences that rely on them. In another line of research, I argued that our conscious perceptions of color properties, such as redness, depend on our representations of the differences and similarities between objects, thereby reversing the traditional order of explanation. I called this view Perceptual Structuralism. I am now expanding my focus to include unconscious neural representations of other properties, such as orientation. In a new strand of research, I am trying to assess the extent to which artificial networks shed light on our own representations and inferences.

The second project is about the foundations of Spinoza's metaphysics. It's an attempt to unravel his claims about minds, bodies, God, and their essences. In past research, I argued for new interpretations of Spinoza's basic notions, namely causation, conception, and inherence. I also argued that Spinoza would reject the Indiscernibility of Identicals in response to a puzzle of identity over time, and that this is the key to understanding his view of the mind's relation to the body. I am now trying to understand his view of essences.

Perceptual Confidence

"Perceptual Confidence,"
Analytic Philosophy (2016), final
*Winner of the 2015 Sanders Prize in Philosophy of Mind

"Perceptual Confidence and Categorization"
Analytic Philosophy (2017), final

Perceptual Structuralism

"Colour in a Physical World,"
Mind (2012), final, appendix

"Anti-Atomism about Color Representation,"
Noûs (2015), final

"Triangulating How Things Look,"
Mind & Language (2015), final

"Perceptual Variation and Structuralism,"
Noûs (2020), final

"Perceptual Variation and Relativism,"
Epistemology After Sextus Empiricus, Vogt & Vlastis (eds.), final, appendix

"Perceptual Variation and Ignorance,"
Synthese (forthcoming), draft

Spinoza's Metaphysics

"Conception and Causation in Spinoza's Metaphysics,"
Philosophers' Imprint (2013), final

"Restricting Spinoza's Causal Axiom,"
Philosophical Quarterly (2015), final

"Truth in the Emendation,"
The Young Spinoza, Melamed (ed.) (2015), final

"Two puzzles about Thought and Identity in Spinoza,"
Cambridge Critical Guide to Spinoza's Ethics, Melamed (ed.) (2017), final

"Descartes on Numerical Identity and Time,"
The Australasian Journal of Philosophy, penultimate

"Spinoza on Numerical Identity and Time,"
Blackwell Companion to Spinoza, Melamed (ed.) (forthcoming), penultimate

"Spinoza on Mind, Body, and Numerical Identity,"
Oxford Studies in Philosophy of Mind (forthcoming), draft

"Three Medieval Aristotelians on Numerical Identity and Time,"
Oxford Studies in Medieval Philosophy (forthcoming), draft


Review of Valtteri Viljanen's Spinoza's Geometry of Power
British Journal for the History of Philosophy (2013), final

Review of De Rosa's Descartes and the Puzzle of Sensory Representation (with Elliot Paul), Mind (2014), final

John Morrison


jmorrison [at]

Barnard Faculty Profile

Columbia Faculty Profile


June 2021


Raphael Gerraty (2019-2021)

PhD Students

Andrew Richmond (advisor)

Natalie Hannan (committee, PhD 2021)

Simon Brown (committee, PhD 2020)

Jorge Morales (advisor, PhD 2018)

Jeremy Wolos (advisor, PhD 2016)