Tim Maudlin

American philosopher and academic

Tim William Eric Maudlin (born April 23, 1958) is an American philosopher of science who has done influential work on the metaphysical foundations of physics and logic.


  • Metaphysics is ontology. Ontology is the most generic study of what exists. Evidence for what exists, at least in the physical world, is provided solely by empirical research. Hence the proper object of most metaphysics is the careful analysis of our best scientific theories (and especially of fundamental physical theories) with the goal of determining what they imply about the constitution of the physical world.
    • The Metaphysics Within Physics (2007) Oxford University Press, p. 104.
  • I believe that it is a fundamental, irreducible fact about the spatio-temporal structure of the world that time passes. ...The passage of time is an intrinsic asymmetry in the temporal structure of the world, an asymmetry that has no spatial counterpart. ...The belief that time passes ...has no bearing on the question of the 'reality' of the past or of the future. I believe that the past is real: there are facts about what happened in the past that are independent of the present state of the world and independent of all knowledge or beliefs about the past. I similarly believe that there is (i.e. will be) a single unique future. I know what it would be to believe that the past is unreal (i.e. nothing ever happened, everything was just created ex nihilo) and to believe that the future is unreal (i.e. all will end, I will not exist tomorrow, I have no future). I do not believe these things... Insofar as belief in the reality of the past and the future constitutes a belief in a 'block universe', I believe in a block universe. But I also believe that time passes, and see no contradiction or tension between these views.
    • The Metaphysics Within Physics (2007) Oxford University Press, pp. 107-109.

Quantum Non-locality and Relativity (2002)Edit

: Metaphysical Intimations of Modern Physics 2nd edition, Blackwell Publishers Inc.

Preface to the First EditionEdit

  • I have often felt that whatever is of value in this book could be found in Bell's "The Theory of Local Beables" (1987, Ch. 7)... this book will have served a great purpose if it does no more than encourage people to read Bell with the care and attention that he deserves.
  • The sparks which fly when quantum theory collides with Relativity ignite conceptual brushfires of particular interest... problems about causation, time, and holism. Unfortunately much of the work... presupposes a considerable amount of familiarity with the physics. This is particularly sad since the physics is not, in most cases, very complicated.
  • The presentation of Bell's inequality needs no more than some algebra... Understanding Relativity also requires no more than algebraic manipulation... but would tax the patience of the average reader. So I have tried to present Relativity pictorially...
  • Pictures of space-time look misleadingly like pictures of space, and the novice must unlearn some of the conventions...
  • Quantum theory... formalism... uses no more than linear algebra and vector spaces. ...A particularly nice and accessible presentation of the requisite mathematics can be found in David Albert's Quantum Mechanics and Experience (1992, Ch. 2).
  • [M]ost clear philosophical ideas can be presented intuitively, shorn of the manifold qualifications, appendices and terminological innovations that grow like weeds in academic soil.
  • At its most fundamental level, physics tells us about what there is, about the categories of being. And modern physics tells us that what there is ain't nothing like what we thought there is.

Preface to the Second EditionEdit

  • Perhaps the most vexing question confronting any study of Bell's inequality, and the experimental observation of violations of that... would never have been discovered if not for the existence of quantum formalism. On the other hand, the inequality... is derived without any mention of quantum theory and the violations are matters of plain experimental fact. So the explication and analysis of the importance of Bell's work can in principle proceed without mentioning quantum mechanics at all. Should an account of Bell's inequality emphasize its historical roots... or... sever those ties in the interest of clarity? ...I chose the second option ...the interpretation of quantum theory is troublesome enough ...to overshadow and confuse the relatively straightforward proof on non-locality.
  • Non-locality appears at exactly the point where the "measurement problem" which infects standard quantum theory is resolved.
  • If one resolves the measurement problem by allowing a real physical process of wave collapse, it is the collapse dynamics which manifests the non-locality, and which resists the fully Relativistic formulation.
  • If one resolves the measurement problem by postulating additional variables beside the wave function, it is the dynamics of these variables which manifests the non-locality and which resists a fully Relativistic formulation.
  • The regrettably widespread opinion that there is no real non-locality inherent in the quantum theory is therefore deeply intertwined with the regrettably widespread opinion that the measurement problem can be painlessly solved without postulating either additional variables or any real collapse process.
  • Although this book is not the place to thrash out those issues, I have thrashed them... in other places.
    • Ref: Maudlin (1995), (1996), (1997) and (1998).


  • Fundamental conceptual changes occur, but they are always modifications of a previously existing structure. ...[T]actical adjustments are made in order to render the whole consistent. The ad hoc nature of this procedure may leave us with lingering doubts as to whether the whole really is consistent.
  • The Theory of Relativity has overthrown classical presumptions about the structure of space and time. The quantum theory has provided us with intimations of a new conception of physical reality. Classical notions of causality, of actuality, and of the role of the observer... have all come under attack.
  • [P]roblems about the fundamental consistency of our two fundamental physical theories may appear. ...It arises from the remarkable results derived by John Stewart Bell in 1964 ...[C]ertain pairs of particles that are governed by quantum laws... appear to remain "connected" or "in communication" no matter how distantly separated... [T]he connection exists even when the observations carried out occupy positions... which cannot be connected by light rays. The particles communicate faster than light.
  • Relativity is commonly taken to prohibit anything from traveling faster than light. ...[H]ow can the particles continue to display the... correlations..? The two pillars of modern physics seem to contradict one other.
  • Many... would agree that Relativity prohibits something from going faster than light but disagree over just what something is.
  • [A]nother interpretation holds that Relativity requires only that
    Theories be Lorentz invarient.
  • Any book which attempts to deal with quantum theory, Special Relativity and General Relativity courts various forms of disaster.
  • [T]he experimental verification of Bell's inequality constitutes the most significant event of the last half-century. ...[O]ur basic picture of space, time, and physical reality must change. These results, and the mysteries they engender, should be the common property of all who contemplate with wonder the universe we inhabit.
  • I hope... to have provided a framework sturdy enough and correct enough to serve both professional and amateur naval architects who propose to redesign the craft which carries us on our journey.

Philosophy of Physics: Space and Time (2012)Edit

Princeton University Press


: The Aim and Structure of These Volumes
  • [T]he most general question we can ask about matter is what sort of thing it is. ...[W]e might hold that matter is made of point-like particles, or of fields, or of one-dimensional strings, or of some combination of these, or of something else altogether. Given any of these ...there are further, more specific questions ...We will be concerned with the most general questions, rather than the more specific ones.
  • [T]he science of thermodynamics... initially aimed at providing a precise account of how heat spreads through an object and from one object to another. But we can discover... detailed equations governing heat flow and still not have an account of what heat is. ...It is a characteristic of contemporary physics education that much more time is spent learning how to solve the equation and get a practical answer... than in... the nature of heat, or the nature of space and time, or the nature of matter. Physics students... fascinated by these foundational questions can find themselves frustrated by... classes that refuse to address them. This volume is dedicated to them as much as it is to philosophers...
  • [T]he need for a completely physical account of "measurement" procedures—are addressed in both volumes...
  • [S]pace and time... do not appear to our senses: they have no color or flavor or sound or smell or tangible shape. ...[They] seem rather to have is a geometrical structure.
  • The Theory of Relativity is presented, first and foremost, as a theory of the geometry of space-time. Special Relativity is explained in enough detail to solve specific problems about the behavior of clocks and rigid objects in a relativistic world. General Relativity is presented less rigorously. My aim... make the conceptual foundations of these theories absolutely clear...

Evidence for Spatial and Temporal StructureEdit

Ch. 2
  • Newton's First Law, the... Law of Inertia, refers only to bodies that are subject to no external forces. It is tempting to say that Newton postulates that such bodies "continue in the same state of motion," but such... would miss the revolutionary aspect... the First Law specifies exactly what counts as "the same state of motion." For Aristotle... a piece of aether in uniform circular motion about [earth,] the center of the universe is always in "the same state of motion," and so there would be no reason to seek out external causes... In Aristotle's physics, external causes are responsible for unnatural motion, such as a rock moving upward instead of down. So for Aristotle, the falling of a stone... requires no external cause, and the continued rotation of a sphere of fixed stars requires no external cause: this what these sorts of matter do by nature.
  • [P]rior to Newton, Galileo sought to specify the "intertial" motion of terrestrial objects—...the motion they would display if subject to no forces—and he concluded that such motion would be uniform circular motion. He arrived at this conclusion from his experimental work with inclined planes.

Philosophy of Physics: Quantum Theory (2019)Edit

Princeton University Press


  • Unlike space-time theory, where there is substantial agreement about how to understand the best physics we have (General Relativity), quantum theory has always been a battleground of contention. Nothing one can say would command the assent of most physicists and philosophers.
  • The central problem facing attempts to understand a quantum theory is how it manages to model empirical phenomena in a principled way. This is often referred to as "the measurement problem"...
  • John Stewart Bell made a proposal... which he called the theory of local beables. "Beables" refers to the ontology of a theory: what it postulates to exist. "Local" indicates a beable that exists in a small region of space-time... What one needs... is an inventory of local beables and an account of their dynamics: how they get distributed in space-time.
  • If the correct solution to the measurement problem does not involve local beables, or if those beables have no nonrelativistic analogs, then starting with nonrelativistic quantum mechanics is counterproductive. But one has to start somewhere...
  • Starting from what we understand and seeing clearly its inadequacies can provide a path to conceptual progress.
  • A physical theory should clearly and forthrightly address two... questions: what there is, and what it does. The answer to the first... the ontology... to the second... its dynamics. The ontology should have a sharp mathematical description, and the dynamics... implemented by precise equations describing how the ontology... evolve[s]. ...All three of the theories we will examine meet these demands.
  • Sometimes, accepting the Copenhagen Interpretation is understood... to use the quantum recipe without... question: Shut up and calculate. Such rejects the aspiration... defined above. Hence it is not even in the running...
  • It has become almost de rigueur in quantum foundations literature to misuse the terms "realist," "realistic," "antirealist," and "antirealistic." These terms have a precise meaning in the philosophy of science... that seems to be... unfamiliar to most physicists. ...[T]hey simply toss them around with no attached meaning ...[with] terrible consequences in foundations of quantum theory.
  • [P]hysical theories are neither realist nor antirealist. That is... a category mistake. It is a person's attitude toward a physical theory that is either realist or antirealist. ...[T]he theory toward which Osiander was antirealist and Galileo realist is one and the same theory. The theory itself is neither.
  • The scientific realist maintains that in at least some cases, we have good evidential reasons to accept theories or theoretical claims as true, or approximately true, or on-the-road-to-truth. The scientific antirealist denies this. These attitudes come in degrees... [T]his is a question addressed by epistemology and confirmation theory...
    • Note: Explained by Maudlin as outside the scope of this book.

Eight ExperimentsEdit

Ch. 1
  • Physics aspires to a sort of universality that is unique among empirical sciences and holds, in that sense, a foundational position among them.
  • Present physics elucidates the "motion" of an object as its trajectory through space-time. A precise understanding... requires a precise account of the structure of space-time. The nature of space-time itself... is the topic of the companion volume... Philosophy of Physics: Space and Time. The present volume addresses the question: What is matter? ...Our main task is to understand just what quantum theory claims about the nature of the material constituents of the world.
  • General Relativity is... completely clear and precise. ...[W]hat the theory says is unambiguous. The more one works with it, the clearer it becomes, and there are no great debates... about how to use it. (The only bit of unclarity... to represent the distribution of matter... using the stress-energy tensor. Einstein remarked that that part... "is low grade wood," while the part describing the space-time structure... is "fine marble.")
  • [N]o consensus... exists among physicists about how to understand quantum theory. There... is no precise, exact physical theory... Instead there is raging controversy. ...How can the manifest and overwhelming success ...be reconciled with complete uncertainty about what the theory claims about the nature of matter?

Quotes about MaudlinEdit

  • I have never bumped into Tim Maudlin, but I have felt his gravitational tug. A Reddit discussion... called Maudlin "probably the most influential person in philosophy of physics." Someone chimed in that Maudlin... is "without a doubt an intellectual beast." Maudlin impresses even... Jim Holt... When I asked Holt "What’s your utopia?," he replied "arguing eternally about gauge theory" with Maudlin and a few other pals. ...Maudlin's ..."The Defeat of Reason"... ends by suggesting that we "shorten the dignified designation Homo sapiens to the pithier and more accurate Homo sap." Ouch.
  • Maudlin's book is likely to upset many physicists and metaphysicians, but in a positive, thought provoking way. Moreover, its plain presentation style makes it a good introductory book for students and non-specialists. In short, it is highly recommended for anybody interested in quantum theory, and especially in what "happens in between."

See alsoEdit

External linksEdit

Wikipedia has an article about: