Mind, Matter, and Meaning

Arnold Zuboff

Arnold Zuboff is a philosopher, long associated with University College London, who works on personal identity and the mind–body problem. He is best known for two lines of argument that he keeps separate. One is universalism, the claim that the boundary between one conscious being and another is an illusion of perspective, so that there is a single subject of all experience. The other is the replacement argument, which defends functionalism by asking what could happen to experience when part of a brain is swapped for a causally equivalent gadget. He also reports that his unpublished work on self-locating examples was the origin of what became known as the Sleeping Beauty problem; Adam Elga’s 2000 paper credits Robert Stalnaker with first learning of such examples from it.

Major Works

  • “Moment Universals and Personal Identity,” Proceedings of the Aristotelian Society 78 (1977–78) — the earlier identity paper, which argues that each moment of experience is a universal and that we are not persons in the ordinary sense.
  • “The Story of a Brain,” in Douglas Hofstadter and Daniel Dennett (eds.), The Mind’s I (1981) — the spread-brain thought experiment.
  • “One Self: The Logic of Experience,” Inquiry 33 (1990) — the settled statement of universalism.
  • “What Is a Mind?,” Midwest Studies in Philosophy 19 (1994) — the worked version of the replacement argument.
  • “Thoughts about a solution to the mind-body problem,” Think 6 (2008) — a short restatement of the replacement argument, built around the Necker cube.
  • Finding Myself: Beyond the False Boundaries of Personal Identity (Philosophy Documentation Center, 2025), with a foreword by Thomas Nagel — the book-length development of universalism, published open access.

Universalism

The usual view holds that you are one particular conscious being, picked out by a body, an origin, or a continuous history. Zuboff argues that this view smuggles in an assumption nothing supports. Before you consider any objective description of yourself, you already know that you are the being whose experience is immediate, the one that seems to sit at the center. Every conscious being has experience with exactly that first-person immediacy. On Zuboff’s account, each experience seems to its owner to be the only one that is mine because it is cut off from the contents of the others, and nothing more is needed to explain that feeling.

His arguments come in several kinds.

  • Brain bisection. Imagine anaesthetizing the corpus callosum so that the two hemispheres briefly work apart. Each side would have immediate experience, and each would feel like the whole of it. Zuboff concludes that the immediacy cannot belong more to one side than to the other, so that being “mine” extends to experiences that cannot reach each other. He credits the structure of the case to a variation on Derek Parfit’s 1971 paper “Personal Identity.”
  • The brain-exchange case. Two exactly duplicate brains are induced to have exactly the same pattern of experience, and parts are swapped between them one piece at a time. Zuboff argues that no stage of the exchange can mark a switch of places, and that the end result is indistinguishable from simply picking the brains up and putting them down in each other’s place. He reads this as showing that qualitatively identical experiences in two brains are one experience, not two.
  • The probability argument. If your existence required that the one right sperm cell win the race in the begetting of you and of each of your ancestors, then your being here would be fantastically improbable. Zuboff argues that the only view that does not make your existence an incredible coincidence is universalism, on which you would have existed whichever organisms happened to arise. He presents this as parallel to inferring that an awakening came from an easy game rather than from a game that required a thousand coin tosses to match a secret code.

A consequence Zuboff draws is that self-interest should extend to all conscious beings, and that the death of one organism does not end the subject, since there is only one.

Development

Zuboff’s view changed in stages, and the stages should not be run together.

  • 1978. In “Moment Universals and Personal Identity” he argues for unification, the claim that exactly repeated experiences make up one experience, and for the conclusion that each moment of experience is a universal. He concludes there that there are no proper continuing persons, and he treats the sense of being a person as a product of evolution.
  • 1983. In Finding Myself he writes that he discovered universalism in 1983. It is the further step that all experience is equally immediate and equally mine, and it replaces the earlier stopping point.
  • 1990. “One Self” develops universalism and its supporting arguments.
  • 2025. Finding Myself sets out the whole case, including the probability argument and a treatment of the Sleeping Beauty problem. Zuboff notes that Elga’s 2000 paper credits Robert Stalnaker with having first learned of such examples from Zuboff’s unpublished work, which appeared in 1990 as “One Self.”

The Replacement Argument

The second line of argument concerns what fixes the character of an experience. Zuboff calls the opposing view intrinsicism: the idea that some intrinsic property of a bit of neural processing, perhaps chemical or biological, or perhaps a distinct mental property, is what gives an experience its character. Functionalism says that only the causal role matters.

The argument runs as a story. Part of your brain, say the left visual cortex, is replaced by a gadget that keeps exactly the same causal relations to the rest of the brain, though its intrinsic properties are radically different. The intrinsicist must tell the story in one of two ways.

  • In “A Change Expressed,” your vision on one side really is altered and you complain about it. This cannot be right, because the gadget is stipulated to be a perfect functional equivalent, so nothing you say, do, or think could differ.
  • In “A Change Unexpressed,” your vision on that side really is altered, but you speak and behave exactly as if it were normal. Zuboff argues that this is not coherent either, because a changed experience could not leave the speech, thought, and behavior grounded in that experience unchanged.

He concludes that functioning preserves the phenomenal character of experience, and that the argument establishes functionalism a priori. “The Story of a Brain” (1981) is an earlier piece in the same neighborhood. It follows a brain divided into hemispheres, then neurons, and asks what would remain of the physical conditions on which a neural theory of experience relies. The story ends with the theory seeming to undermine itself, since it appears to provide experience so cheaply that no experiencer could trust the physiology on which the theory rests. Zuboff says in 1994 that his own position blends Gilbert Harman’s functionalism with Thomas Nagel’s insistence on fidelity to the subjective character of experience.

The two lines of argument are logically separate. Preserving experience under replacement does not show that every conscious being is the same subject, and universalism does not by itself fix what makes a particular experience the one it is.

Reception and Criticism

Nagel’s foreword to Finding Myself grants that “both the conclusion and the argument will certainly seem incredible, even outrageous, to many readers.” He nonetheless calls the book “a philosophical contribution of the first order” and says that the relation of mind to world is so mysterious that no view, however radical, should be dismissed out of hand.

Critics press several points. The probability argument depends on contested principles for reasoning about one’s own identity and about self-locating evidence. The bisection and exchange cases rest on thought-experiment verdicts that a reader may resist. Nick Bostrom argues that duplicated experience adds further experience instead of merging with the original, a dispute Zuboff addresses directly in Finding Myself. On the replacement argument, a defender of intrinsic or biological views can deny that the stipulated functional equivalence leaves experience unchanged, or can reject the step from unchanged reports to unchanged experience. David Chalmers’s “fading qualia” and “dancing qualia” arguments are close relatives of the replacement argument, though Chalmers draws a different overall picture of the mind from them.

  • The Self — what “the self” can name, and how the personal-identity question differs from the subject question.
  • Functionalism — the view that mental states are individuated by causal role.
  • Qualia — phenomenal character and what it might depend on.
  • Physicalism — the wider family of views that Zuboff’s functionalism belongs to.
  • Nagel — graduate supervisor, author of the foreword to Finding Myself, and the author of the “I am Thomas Nagel” passage on token-reflexive facts that Zuboff discusses in “One Self.”
  • Harman — graduate supervisor, and the functionalist influence Zuboff names.

Further Reading

  • Zuboff, Arnold. “Moment Universals and Personal Identity.” Proceedings of the Aristotelian Society 78 (1977–78): 141–155.
  • Zuboff, Arnold. “The Story of a Brain.” In The Mind’s I: Fantasies and Reflections on Self and Soul, edited by Douglas R. Hofstadter and Daniel C. Dennett, 202–212. Basic Books, 1981.
  • Zuboff, Arnold. “One Self: The Logic of Experience.” Inquiry 33, no. 1 (1990): 39–68.
  • Zuboff, Arnold. “What Is a Mind?” Midwest Studies in Philosophy 19 (1994): 183–205.
  • Zuboff, Arnold. “Thoughts about a Solution to the Mind-Body Problem.” Think 6, no. 17 (2008): 159–171.
  • Zuboff, Arnold. Finding Myself: Beyond the False Boundaries of Personal Identity. Foreword by Thomas Nagel. Philosophy Documentation Center, 2025. Open access (CC BY-NC-ND): https://www.pdcnet.org/wp/wp-content/uploads/2025/12/Zuboff_MSP-Supplement_2025.pdf.
  • Parfit, Derek. “Personal Identity.” The Philosophical Review 80, no. 1 (1971): 3–27.
  • Elga, Adam. “Self-Locating Belief and the Sleeping Beauty Problem.” Analysis 60, no. 2 (2000): 143–147.